I've fixed a lot of slow computers over the years, and honestly? Most of the time, it's not the computer's fault. It's the things people do (or don't do) that make Windows crawl. The good news is these are all easy to fix.

Here are the 10 most common mistakes I see, and how to avoid them. Fix these, and your computer will run noticeably faster.

1. Never Restarting Your Computer

I know people who go weeks without restarting. Windows needs to restart occasionally to clear memory, install updates, and reset things. If you never restart, stuff builds up and slows everything down.

The fix: Restart at least once a week. More if you use your computer heavily. I restart mine every few days, and it makes a difference.

Pro tip: If your computer's acting weird, restart it first. Half the time, that fixes it.

2. Installing Too Many Startup Programs

Every program that starts with Windows uses resources. The more you have, the slower your computer boots and the more RAM it uses.

The fix: Press Ctrl+Shift+Esc to open Task Manager, go to the Startup tab, and disable anything you don't need starting automatically. Things like Steam, Discord, Spotify - you can open them when you need them.

What to keep: Antivirus, Windows security stuff. That's about it. Everything else can wait.

3. Never Cleaning Up Disk Space

When your hard drive gets full (especially your C: drive), Windows slows down. It needs free space to work properly.

The fix: Use Disk Cleanup (search for it in the Start menu). It removes temporary files, old updates, and other junk. Run it every few months. Also, uninstall programs you don't use anymore.

How much space to keep free: At least 10-15% of your drive. More is better.

4. Running Multiple Antivirus Programs

More antivirus doesn't mean more protection. Running two antivirus programs at once makes them fight each other and slows everything down.

The fix: Pick one antivirus. Windows Defender (built into Windows) is actually pretty good and free. If you want something else, uninstall Windows Defender first, then install the other one.

My recommendation: Just use Windows Defender. It's free, doesn't slow things down much, and works well. Unless you're doing something risky, it's probably enough.

5. Not Updating Windows

I know updates are annoying, but they fix security holes and performance issues. Skipping them means you're missing out on improvements.

The fix: Let Windows update automatically. Go to Settings → Update & Security → Windows Update and make sure it's set to automatic. Or at least check for updates weekly.

When to update: When you're not using your computer. Updates can take a while, so schedule them for when you can let it run.

6. Too Many Browser Extensions

Browser extensions use memory and can slow down browsing. The more you have, the slower your browser gets.

The fix: Go through your extensions and remove ones you don't actually use. Keep only the ones you need. In Chrome: Settings → Extensions. In Firefox: about:addons

What to watch for: Some extensions are resource hogs. If your browser is slow, disable extensions one by one to find the culprit.

7. Never Defragmenting (HDD Users)

If you have an old hard drive (not an SSD), it needs defragmenting occasionally. SSDs don't need this, but old spinning drives do.

The fix: Search for "Defragment" in Start menu, open "Defragment and Optimize Drives", and run it on your hard drives (not SSDs). Windows usually does this automatically, but check to make sure.

How to tell if you have an SSD: If your computer boots in under 30 seconds, you probably have an SSD. Or check in Task Manager → Performance → Disk. If it says "SSD", you don't need to defragment.

8. Leaving Too Many Programs Open

Every open program uses RAM. If you have 20 browser tabs, Photoshop, Excel, and a bunch of other stuff open, your computer will slow down.

The fix: Close programs you're not using. Check Task Manager (Ctrl+Shift+Esc) to see what's using the most memory and close the big ones.

How much RAM do you need? 8GB is minimum these days. 16GB is comfortable. If you have less than 8GB, that's probably why your computer is slow.

9. Ignoring Windows Updates

I mentioned this already, but it's worth repeating. Updates aren't just annoying - they're important. They fix bugs, security issues, and sometimes improve performance.

The fix: Don't keep clicking "Remind me later". Just let it update. Set it to update automatically when you're not using the computer.

If updates break something: You can usually roll back. Settings → Update & Security → Recovery → Go back to previous version (if available).

10. Not Managing Visual Effects

Windows has a lot of fancy animations and effects. They look nice, but they use resources. On older or slower computers, turning them off helps.

The fix: Right-click This PC → Properties → Advanced system settings → Performance Settings. Choose "Adjust for best performance" or "Custom" and uncheck the effects you don't need.

What to keep: I usually keep "Smooth edges of screen fonts" because text looks better. Everything else can go if you need the speed.

Quick Performance Checklist

Do these regularly:

• Restart your computer weekly
• Clean up startup programs
• Run Disk Cleanup monthly
• Keep at least 15% of your drive free
• Update Windows regularly
• Close programs you're not using
• Remove browser extensions you don't need