Cursor Won't Install? Won't Start? Here's How to Fix the Bullshit

Windows and Cursor get along like a house on fire - badly, with lots of screaming.

The "Windows Protected Your PC" Nightmare

You download Cursor, double-click it, and boom - Windows SmartScreen throws up a scary warning like you're trying to install ransomware. This is Windows being Windows. The software is fine, Microsoft just doesn't recognize it because not enough people have downloaded it recently.

What actually works:

• Click "More info" then "Run anyway" - don't overthink this shit
• Or just right-click and "Run as Administrator" from the start (saves time)
• Your antivirus will lose its mind too - just add exceptions or disable it temporarily
• Disable Windows Defender Real-time protection temporarily during installation
• Check Windows SmartScreen settings and lower security level if needed
• Review code signing certificate issues that trigger these warnings

I've seen teams waste hours on this. It's not a security issue, it's Microsoft's reputation system being overly paranoid.

When Installation Just... Stops

Real scenario I've debugged multiple times: Installer progress bar gets to 50%, sits there for 5 minutes, then either crashes or appears to complete but Cursor is nowhere to be found.

This happens when:

• You don't have enough disk space (Cursor needs like 1GB+ even though they say 400MB)
• Windows Update is pestering you for a restart - just do it
• Your disk might be dying (run `chkdsk /f` if you're feeling paranoid)
• Some other installer is stuck in the background (I spent 20 minutes once tracking down a hung MSI installer)

Nuclear option that works:

## Run as Administrator - this clears any partial installation mess
rd /s /q "%USERPROFILE%\AppData\Local\Programs\Cursor\"
rd /s /q "%USERPROFILE%\AppData\Local\Cursor\"

Then restart your computer and try again. I know it's annoying, but Windows gets confused easily.

macOS: Gatekeeper Being a Dick

macOS thinks Cursor is going to steal your credit cards and murder your family. It's not - Apple just doesn't trust anything that isn't from their walled garden.

The "Can't Be Opened" Bullshit

You download the installer, try to run it, and macOS goes "Nope, this could be malicious." It's not malicious - Apple just wants you to buy everything through their App Store so they can take their 30% cut.

What actually works:

• Right-click the installer and choose "Open"
• When the scary warning shows up, click "Open" again (they make you confirm twice)
• If it's still being a pain, go to System Preferences → Security & Privacy and click "Allow Anyway"

Pro tip: This happens with literally every development tool on macOS. Get used to it.

When Cursor Installs but Won't Start

Story time: I once spent 3 hours debugging why Cursor would show up in Applications but clicking it did absolutely nothing. Turns out macOS had quarantined the entire app because it didn't trust the developer signature.

The fix that actually works:

## Remove Apple's paranoid quarantine flag
xattr -d com.apple.quarantine /Applications/Cursor.app

If you're on Apple Silicon and it still won't start, you might need Rosetta 2:

## Install compatibility layer for Intel apps
softwareupdate --install-rosetta --agree-to-license

Debugging pro tip: Launch from Terminal to see actual error messages:

/Applications/Cursor.app/Contents/MacOS/Cursor

This will show you what's actually broken instead of silent failures.

Linux: Where Everything Should Work but Doesn't

Linux is supposed to be the developer paradise, but somehow Cursor still finds ways to break.

AppImage Won't Run? Welcome to Linux

You download the AppImage, double-click it, and... nothing. Linux doesn't trust executable files by default, which is both secure and incredibly annoying.

Fix this shit:

chmod +x cursor-*.AppImage
./cursor-*.AppImage

If it still won't run, you're missing FUSE (because of course you are):

## Ubuntu/Debian
sudo apt install libfuse2 libasound2-dev

## If you're on newer Ubuntu that decided to break everything
sudo apt install fuse
## Or just bypass FUSE entirely
./cursor-*.AppImage --no-fuse

Package Managers Are Broken

Don't bother with apt install cursor or whatever your distro promises. The package repositories are always outdated or broken.

Just grab the AppImage directly from official downloads:

## Download latest AppImage from cursor.com/downloads  
## Select "Linux AppImage (x64)" and copy the direct link
chmod +x cursor-*.AppImage
./cursor-*.AppImage

If your system is completely fucked and nothing works:

sudo apt --fix-broken install
sudo apt update && sudo apt upgrade

Last resort - Snap:

sudo snap install cursor --classic

Snap is slower than molasses but it usually works.

Corporate Networks: Where Dreams Go to Die

When IT Blocks Everything

Your corporate firewall treats Cursor downloads like they're ISIS recruitment videos. They're not being paranoid for fun - they just don't understand what developers need.

Solutions that actually work:

Option 1: Download from mobile hotspot, install offline

• Most companies can't complain about software you installed at home
• Just don't tell them about it

Option 2: Give your IT team this domain list:

*.cursor.sh
*.cursor.com  
*.cursorapi.com
anysphere-binaries.s3.amazonaws.com

Option 3: Find someone with admin rights who gives a shit about productivity

SSL Certificate Bullshit

Corporate proxies love to man-in-the-middle your HTTPS connections with their own certificates. This breaks downloads and makes Cursor think it's under attack.

Quick check: Try downloading from a browser first. If you get certificate warnings there, it's your corporate proxy being "helpful."

Workaround: Download on personal network, transfer via USB stick. Old school but it works.

Proxy Hell

If your company forces everything through a proxy, the installer will probably choke when trying to verify the installation or download components.

Environment variable fix:

export http_proxy=http://proxy.company.com:8080
export https_proxy=https://proxy.company.com:8080

Replace proxy.company.com:8080 with whatever nightmare URL your IT team gave you.

How to Tell If Installation Actually Worked

Quick Test

Windows:

cursor --version

macOS/Linux:

cursor --version

If this shows a version number, you're probably good. If it says "command not found," the installation is fucked.

Full Test

Launch Cursor. You should see:

• A welcome screen (not an error message)
• It asks for file access permissions (say yes)
• Option to sign in or skip

If instead you see "connection failed" or the AI features don't work, that's a network problem - different issue entirely.

The Bottom Line

90% of installation problems boil down to:

1. Windows: Run as Administrator and tell your antivirus to fuck off
2. macOS: Override Apple's security theater in System Preferences
3. Linux: Make the file executable and install missing dependencies
4. Corporate: Download from home network, install offline

Don't waste time debugging mysterious errors - just nuke the installation directory and start fresh. Life's too short.

Your corporate network was designed by people who think developers are trying to download malware 24/7. They're not wrong, but they're also making your life hell.

Why Corporate Firewalls Hate Cursor

Cursor does everything that makes corporate IT nervous:

• Uses HTTP/2 (because HTTP/1.1 is apparently too mainstream)
• Makes constant connections to random AI servers
• Streams data in real-time (suspicious!)
• Uses WebSockets (definitely malware behavior)
• Bypasses traditional proxy authentication mechanisms
• Makes SSL/TLS connections that corporate firewalls can't inspect
• Uses non-standard ports for some connections
• Implements certificate pinning that breaks corporate MITM proxies
• Creates persistent connections that stay open for hours
• Uses Server-Sent Events for real-time AI responses

The result: Your firewall sees Cursor traffic and thinks "this looks like a botnet command-and-control channel" and blocks everything.

The HTTP/2 Nightmare

Here's the thing that'll ruin your day: Cursor requires HTTP/2 to work properly. Most corporate proxies were configured in 2015 and treat HTTP/2 like it's radioactive.

What HTTP/2 gives you:

• AI responses stream in real-time instead of waiting forever
• Tab completion actually works at human speed
• Multiple requests don't block each other

HTTP/2's multiplexing allows multiple requests to be processed simultaneously over a single connection, while HTTP/1.1 processes them sequentially - this is why AI features feel so much faster.

What happens when your proxy blocks HTTP/2:

• Connection timeouts
• "Failed to connect" errors
• AI features randomly stop working
• You question your life choices

Corporate proxy bullshit:

• Zscaler: Blocks HTTP/2 by default (why?)
• BlueCoat: Breaks WebSockets
• Squid: Ancient garbage that strips headers
• Plus whatever nightmare your company uses

The Domains Your IT Team Will Ignore for 6 Months

Copy this list and send it to your IT team. They'll probably ignore it until you escalate to someone who actually gives a shit about developer productivity:

## The shit that needs to be whitelisted
*.cursor.sh          # Everything important
*.cursor.com         # Auth and billing  
*.cursorapi.com      # Extensions and marketplace
*.gcpp.cursor.sh     # Regional servers (probably blocked)
anysphere-binaries.s3.amazonaws.com  # Updates and downloads

Just whitelist *.cursor.sh and *.cursor.com - don't make this harder than it needs to be.

What your IT team will say:

• "We need to evaluate security implications" (translation: we'll ignore this for months)
• "Can you use a different tool?" (translation: we don't understand what you do)
• "This violates our security policy" (translation: our policy was written in 2008)

Pro tip: Find someone with actual authority who cares about getting work done. Skip the help desk.

VPN Hell: When Your Security Tools Hate You

VPNs and Cursor get along like cats and dogs - they technically coexist but there's a lot of hissing and scratching.

Corporate VPNs typically route all traffic through centralized gateways and corporate firewalls, which often block the protocols and domains that Cursor needs for AI functionality.

Why VPNs Break Everything

Corporate VPNs are designed to lock down your connection, not enable productivity:

• Force all traffic through corporate firewalls (that block Cursor)
• Use DNS servers that don't resolve Cursor domains properly
• Throttle "suspicious" AI traffic
• Route you through geographic regions Cursor doesn't serve

Split tunneling is your friend - if your VPN supports it, bypass these domains:

cursor.sh
cursor.com
cursorapi.com

But let's be honest - most corporate VPNs don't let you configure jack shit.

The "Try a Different VPN Server" Dance

Sometimes your VPN exit point is in a region that Cursor's CDN doesn't serve well. Try switching servers until you find one that doesn't suck.

Geographic lottery:

• US East Coast: Usually works
• US West Coast: Usually works
• Europe: Hit or miss
• Asia: Good luck
• Anywhere else: Probably fucked

DNS Bullshit

Your VPN might be hijacking DNS and routing Cursor domains to nowhere. Try switching to public DNS while connected:

• 8.8.8.8 (Google)
• 1.1.1.1 (Cloudflare)
• 208.67.222.222 (OpenDNS)

If Cursor suddenly works, your VPN's DNS is garbage.

The HTTP/1.1 Fallback Band-Aid

When HTTP/2 is completely fucked, you can force Cursor to use HTTP/1.1. It's slower, but at least it works.

How to enable the fallback:

1. Open Cursor settings (Ctrl/Cmd + ,)
2. Search for "HTTP/2"
3. Check "Disable HTTP/2"
4. Restart Cursor and pray

What you lose with HTTP/1.1:

• AI responses come all at once instead of streaming (painful for long responses)
• Tab completion becomes noticeably slower
• Multiple AI requests queue up instead of running in parallel
• Background agents take forever

But hey, at least it works.

Testing if Your Network Is Actually the Problem

The built-in network diagnostics in Cursor are about as useful as a chocolate teapot. They'll tell you everything is "Connected" while nothing actually works.

Real network testing:

## Test basic connectivity to Cursor
curl -I https://docs.cursor.com

## Check if HTTP/2 works  
curl --http2 -I https://docs.cursor.com

## Test if your DNS can resolve cursor domains
nslookup cursor.com

What to look for:

• HTTP 200 or 404 = connection works
• Connection timeout = firewall blocking
• Certificate errors = proxy interference
• HTTP/2 in headers = your network supports it

When Everything is Broken

Nuclear options when nothing else works:

Option 1: Mobile hotspot test

• If Cursor works on mobile but not corporate network, it's definitely the firewall
• Use this as evidence when talking to IT

Option 2: Work from home

• If your company allows it, work from home network
• Corporate VPN might still break things, but at least you can bypass the office firewall

Option 3: Find a new job

• If your IT department is completely inflexible about developer tools
• Life's too short to fight firewalls every day

The harsh reality: Some corporate networks are so locked down that Cursor will never work properly. Your IT team prioritizes security theater over productivity, and there's not much you can do about it except find workarounds or find a new place to work.

Cursor is built on Electron, which means it's basically Chrome pretending to be a text editor. And like Chrome, it wants to eat all your RAM and ask for seconds.

Pro tip: Check your system monitor (Activity Monitor on macOS, Task Manager on Windows) to see Cursor's actual memory usage - it's probably worse than you think.

To check Cursor's memory usage:

• Windows: Open Task Manager (Ctrl+Shift+Esc) → Processes tab → Look for "Cursor" entries
• macOS: Open Activity Monitor → Search for "Cursor"
• Linux: Use htop or ps aux | grep cursor

Cursor's Appetite for Destruction

What Cursor does to your system:

• Starts around 2GB RAM (just to launch)
• Grows to like 4-5GB during normal use
• After a few hours with AI chat? 8GB easy, sometimes more
• With big codebases I've seen it hit 12-15GB (goodbye everything else)

Why it gets worse over time:

• Chat history never gets cleaned up (every conversation lives forever in memory)
• AI context keeps growing (your entire codebase lives in RAM)
• Extensions pile on their own memory overhead
• Background agents leak memory like a sieve
• Electron's memory management is fundamentally broken
• JavaScript garbage collection can't keep up with AI processing
• WebView processes accumulate memory over time
• Node.js memory leaks in extension host processes
• V8 engine limitations with large object heaps
• Chrome DevTools memory profiling can help identify specific leaks

Real story: I've seen Cursor consume 16GB on a developer's machine with 32GB total RAM. The rest of the system was paging to disk constantly. His laptop fan sounded like a jet engine.

When Your System Gives Up

How to tell Cursor is killing your machine:

• Loading screen freezes (system ran out of memory to allocate)
• Crashes after a few minutes (hit the memory limit hard)
• Your entire computer becomes unresponsive (OS is desperately paging to disk)
• You get "out of memory" errors (Electron's polite way of saying "I broke your system")

RAM requirements - the brutal truth:

• 4GB total: Don't even bother, it's a nightmare
• 8GB total: Cursor works but good luck running Chrome too
• 16GB total: Finally usable - you can have Cursor and maybe some browser tabs
• 32GB total: Now you're comfortable - Cursor can eat half your RAM and you won't care

Survival strategies:

• Close Chrome (yes, all 47 tabs)
• Kill Slack, Discord, and any other Electron apps
• Restart Cursor daily or it'll consume your entire system
• Start new chat conversations instead of letting them grow forever

The Chat History Memory Leak from Hell

Here's a fun bug: Cursor never forgets your chat history. Ever. That 3-hour debugging session where you asked 200 questions? Still in memory. That time you pasted your entire codebase into chat? Also still there.

How this ruins your day:

• Each chat message stays in memory forever
• Long conversations make Cursor progressively slower
• Eventually your system starts paging because Cursor has consumed everything
• Cursor crashes when you hit system memory limits

War story: I once had a chat conversation that lasted 2 weeks (working on a complex refactor). By the end, Cursor was using 12GB RAM just for the chat history. When it finally crashed, I lost everything because it doesn't auto-save conversations.

Damage control:

• Start fresh chat conversations regularly (don't let them grow past 50-100 messages)
• Copy important stuff out before starting over
• Restart Cursor if it's using more than 8GB RAM
• Monitor memory usage - Task Manager on Windows, Activity Monitor on macOS

CPU Usage: When Your Laptop Becomes a Space Heater

Cursor loves to peg your CPU at 100% for mysterious reasons. Your laptop will start sounding like a jet engine, and your battery will drain faster than water through a sieve.

What makes Cursor go crazy:

• Background indexing: Cursor indexes your entire codebase constantly, even files you'll never touch
• Rogue extensions: That VS Code extension you installed 6 months ago is now eating 50% CPU
• File watching: Monitoring every single file in your project for changes, including node_modules
• AI processing: Sometimes background agents just get stuck in loops

How to find the CPU hog:

1. Open Process Explorer: Command Palette → Developer: Open Process Explorer
2. Look for processes using high CPU:
   • extensionHost = extension problem
   • ptyHost = terminal issue
   • Main process = Cursor itself is broken

Pro tip: Use Process Explorer (Windows) or Activity Monitor (macOS) to see which specific processes are consuming CPU.

Extension debugging:

• Enable Extension Monitor in Settings → Application → Experimental
• Command Palette → Developer: Open Extension Monitor
• Look for extensions with high % CPU - those are the culprits

Nuclear option: Start with cursor --disable-extensions and see if the CPU usage drops. If it does, you have a rogue extension.

Indexing Hell: When Cursor Tries to Read the Internet

Cursor wants to index every single file in your project to give the AI context. This sounds great in theory, but in practice it means Cursor tries to read through your entire node_modules directory, build artifacts, and that 2GB log file you forgot about.

Horror story: I opened a monorepo with 500k files (including node_modules for 20+ packages). Cursor spent 4 hours indexing and consumed 24GB of RAM before I force-killed it.

Save yourself with .cursorignore:

## Put this in your project root - NOW
node_modules/
.git/
dist/
build/
target/
*.log
.env*
coverage/
.next/
vendor/
__pycache__/
.vscode/

Signs your indexing is fucked:

• Status bar shows "Indexing..." for hours
• System becomes unresponsive when opening large folders
• Cursor uses more CPU than a cryptocurrency miner
• You can hear your hard drive crying

Pro tip: If you have a monorepo, don't open the root directory. Open individual packages as separate workspaces or Cursor will try to index everything and die.

Graphics Drivers: When Your Screen Goes Black

Cursor is basically Chrome in disguise, which means it needs modern graphics drivers to not crash. If you're running graphics drivers from 2018, expect problems.

Signs your graphics drivers are fucked:

• Cursor shows a black screen instead of the interface
• Random crashes when switching between windows
• UI elements render as garbage or don't appear at all

Fix this shit:

• NVIDIA: Download GeForce Experience, let it update everything
• AMD: Get AMD Software from their website
• Intel: Use Intel Driver & Support Assistant (if you're desperate)

If updating drivers breaks more than it fixes, disable hardware acceleration:

• Add "cursor.window.useHardwareAcceleration": false to settings
• Or launch with cursor --disable-gpu

Extension Hell: When VS Code Extensions Attack

Extensions can turn Cursor into a slow, buggy mess. That innocent-looking syntax highlighter? It's probably eating 30% of your CPU.

The Extension Bisect method (when shit is broken):

1. Command Palette → Help: Start Extension Bisect
2. It disables half your extensions to isolate the problematic one
3. Keep bisecting until you find the culprit
4. Uninstall the broken extension and move on with your life

Common extension problems:

• Syntax highlighters: Complex language extensions that parse everything constantly
• Real-time sync tools: Extensions that never stop talking to servers
• File watchers: Extensions monitoring every single file change
• AI extensions: Two AI tools fighting each other for resources

Pro tip: Start with cursor --disable-extensions when troubleshooting. If the problem goes away, you have a rogue extension.

The Bottom Line on Performance

Cursor's performance is usually limited by:

1. Your system not having enough RAM (get 16GB minimum)
2. Rogue extensions eating CPU/memory (disable them)
3. Indexing huge codebases (use .cursorignore)
4. Old graphics drivers (update them)

Don't keep reinstalling Cursor when it's slow - fix the underlying problem.