🪟 Install MongoDB on Windows

Problem: MongoDB is not in your system PATH.

Solution - Add MongoDB to PATH:

1. Press Windows + R
2. Type: sysdm.cpl and press Enter
3. Click "Advanced" tab
4. Click "Environment Variables"
5. Under "System variables", find and select "Path"
6. Click "Edit"
7. Click "New"
8. Add: C:\Program Files\MongoDB\Server\8.0\bin
9. Click OK on all windows
10. Close and reopen Command Prompt/PowerShell

# Close and reopen CMD, then run:
mongod --version

# Should now work!

Common Causes:

• Port 27017 is already in use
• Data directory doesn't exist or no permissions
• Another MongoDB instance is running

Solution 1 - Check Port:

# In Command Prompt (as Administrator):
netstat -ano | findstr :27017

# If something is using port, kill it:
taskkill /PID [process_id] /F

Solution 2 - Recreate Data Directory:

# In PowerShell (as Administrator):
mkdir "C:\Program Files\MongoDB\Server\8.0\data"
mkdir "C:\Program Files\MongoDB\Server\8.0\log"

# Then restart MongoDB service:
net stop MongoDB
net start MongoDB

Problem: You don't have Administrator privileges.

Solution:

1. Right-click on Command Prompt or PowerShell
2. Select "Run as Administrator"
3. If still issues, disable antivirus temporarily
4. Make sure Windows Defender isn't blocking MongoDB

Problem: Can't connect to localhost:27017

Solutions:

1. Verify MongoDB Service is Running:

# PowerShell:
Get-Service MongoDB

# Status should be "Running"
# If stopped, start it:
Start-Service MongoDB

2. Check Connection String:

Make sure you're using correct connection string:

OR

3. Firewall Issues:

Add MongoDB to Windows Firewall exceptions if blocked.

Problem: Installer stuck downloading Compass.

Solutions:

1. Be Patient: It can take 10-15 minutes on slow connections
2. Check Internet: Installer downloads Compass from internet
3. Alternative: Cancel installer, reinstall WITHOUT Compass checkbox
4. Manual Install: Download Compass separately from MongoDB Compass Download Page