Slow running computer, What else can i try?

WindowsXP home

92% available space

pentium 4 @ 3.6 Ghz

256mb of RAM

Okay here goes, I have completely erased my hard drive, re-installed the OS, acquired all of the necessary updates for the OS. Installed updates for the drivers i need, have AVG 7.5 anti virus protection running. I run scan disk on it and keep temporary internet files deleted, cookies dumped, and analyze my hard drive once a week for a defrag and do it if needed.

My system runs sooooo slow even though i do all of these things.

I did a free registry scan and it shows almost 300 invalid registry items. Is there a way to remove these items without purchasing a new program?

OR.... is this not my problem? Please help.

Slow running computer, What else can i try?anti virus

SLOW because your PC is frequently accessing SLOW Virtual Memory. Upgrade RAM to 2x512mb. Your PC would suddenly be amazing.

Also disable unnecessary startups in msconfig.

Slow running computer, What else can i try?auto protect

Check out http://www.pc-optimizer-pro.info

With pc optimizer pro you can safely clean, repair and optimize your computer.

It will help improve your system performance without expensive hardware upgrades.

Good luck!
sounds like you have a virus. try avast free virus protection, better than avg cause it alerts you when a virus is trying to get in and deletes it before it can do harm
Try this computer speedup tool: