Computer Randomly Locks Up

My OS:Windows XP
Hardware: P4 2GHz processor, 512 RAM

Hello,
I'm having a problem where everything on my screen "freezes" and cannot recover except with a reboot. This happens randomly, sometimes after 5 minutes of being on other times after 2 days of being on. When it locks up the monitor displays whatever page I was on last and does not go into screensaver mode. This occurs no matter which program I am running.

So far I have:
1)Replaced the video card
2)Removed all dust/debris inside my PC
3)Did all spyware/virus steps and programs listed in this site
4)Completely reloaded Windows

Any ideas or suggestions are very appreciated!

 

I know I'm only an E-2 here but I'm only new to this forum. I've been around computers since TI introduced the 99-4A back in about 82or 83.

Try cleaning the contacts on the memory. What I do is remove the memory module and use a pink pencil eraser to LIGHTLY clean the gold connections. In my experience, this fixes random lockups a lot of the time. You should wear a properly grounded wrist strap while doing this.

 

Thanks, I will try that.