Memory problems

I haven't posted here for a while, but I'm hoping its still active enough for me to get a few suggestions on my problem.

Right, situation: my current pc (custom-built by me) has been working fine for around a year since building. Then suddenly this Monday I started getting 'memory can't be read' errors, generally from game programs (mainly World of Warcraft), but then progressing into random crashes and memory errors in general usage (web browsing, MSN etc.).

I have 2 512mb memory sticks, and have run memtests on both (separately and together) and have tried using only 1 at a time, but I get the errors with either and in any memory slot. I'm starting to think it may be a harddrive problem.

Any suggestions/solutions?

"Memory can't be read" could indeed mean that swap can't be read. This would be either a filesystem problem or the drive can be physically damaged. The first one might be more pleasant for you. On the other hand, Windows might just have screwed something up. In this case reinstallation might be the fastest way to fix it.

Have you checked that there isn't any spyware or viruses on your computer?

I agree that the problem isn't likely to be in your memory sticks.

I have checked for viruses and spyware recently and the program did notice a change in the shell32.dll. However, its a freeware program and seems to offer no information on the change/virus detected. I've done some drive scans on both my harddrives but to no avail so far. I will try defrag later. I'm certainly considering a format and reinstall of windows. But in terms of windows causing the problem, it seems odd that the errors would just suddenly start some random evening, especially as it had been working fine that say day, I go out and when I come back the errors start. To me it points to a hardware issue.

I've seen these before, and it usually is related to the OS, if its the memory at (location) cannot be "read" error, it usually relates to a program trying to read memory it doesn't own, the change in shell32.dll should raise some flags though, as thats like, a very core file... I'd suggest a reinstall, not nesecerrily a reformat yet, just a windows repair from the CD, which should reload all the original windows system files before you do a wipe

I seem to have stabilised it for the time being, by underclocking (frequency moved down to 166mhz, was 200), but that points to maybe a heating issue. I'm checking my fans.