freezing + booting problems...memory issue?

Just last night I started having weird problems. If I end up having to restart/shut down via the button, the next time it boots it freezes partway through. Either it'll get through the Windows (XP SP2) loading thing with the scrolling progress bar, then freeze at a black screen (the one right before the login screen appears), or the loading screen never goes away (but doesn't freeze since the progress bar still moves). The hard drive light just stops blinking. If I shut the computer off for a while it works fine for a while before happening again. I haven't done anything different, so I don't know why it would suddenly start having issues now.

I've had the freezing black screen before on my laptop, and a registry cleanup seemed to help. I did a registry scan with RegScrubXP, and after making a backup, tried fixing all of them. It would fix them until, but when it got to a certain one the computer would restart itself, but boot into Windows fine. I can't remember the entry because I'm reporting from my laptop (I unplugged the other system for a while), something like ShimLoad or similar, with an error of "no values or subkeys for this key". I'll post the full information once I boot it up again. Other registry scanners like Registry Booster, CCleaner, and Spybot (the last two not primarily for registry, I know) don't find it.

I'm thinking it's a memory issue dealing with the registry, with shutting the system down clearing the RAM. On my laptop the black screen freeze was a memory issue according to the BSOD, but again that was fixed by repairing the registry.

Yes, I did virus/spyware scans and the like, with no issues. It could be coincidence, but when the system reaches about 95°F (35°C) it starts to act up. I don't think that has anything do with it, but I thought I'd mention it. I also noticed that the system freezes quite a bit while running Firefox (don't get any ideas, IE fanatics), but maybe it's because I'm always running it as an icon in the taskbar with an extension. Anyone ever have system freezing issues with Firefox? The booting issue also occurs whenever the system freezes no matter what the source (like Far Cry, but then again it randomly decides whether it wants to freeze five minutes into gameplay).

What are some memory scanners you guys recommend? I doubt I'd actually have to replace a memory stick(s) (2GB Corsair), but there's always the possibility of bad sectors.

Let me know if you need more system information.

Thanks!!

 

The registry entry is "ShimFlushCache", which along with the other "Shim" entries apparently have to do with WMP 10. I think what I might've done is let it be deleted when Spybot asked on startup. I know it's what caused it to come up in RegScrubXP, so maybe I can blame WMP. A bunch of other "Shim" entries came up, but I don't want to find out if they restart my computer. I guess they're needed regardless of whether they're populated, so I'll leave them alone.

I tried allocating "all unused RAM" in MemTest, and since 1037MB wouldn't work, I set it to 500MB. Is that a good amount for a 2GB machine not running anything power consuming (mail client, web browser, antivirus, antispyware, anything non-gaming)? I started it a few minutes ago and it's at 110% with no errors (which really isn't much, but it's a good start I guess). It's running a lot slower than my laptop with 512MB and overall slower hardware if that means anything (as in by now it would be at 2000% or so), with just as much load.

Now that Photobucket felt like working, here's what the RegScrubXP errors are, minus ShimFlushCache since I told Spybot not to delete it:

 

I got halfway through typing an e-mail when the system decided to freeze again. MemTest didn't report anything when it happened (I think it got to about 250%), but now I'll let it run and not use the computer for a while and see what happens.

 

Well, the system froze as the Memtest was working with no other programs running, but for some reason the two instances of it were the only things clickable. No errors, but again I've restarted. I'm running the Ubuntu on-boot memory testt, and the memory settings reports are way off (163 MHz DDR326 CAS 7-7-7 when they're supposed to be 800MHz DDR2-cantremember CAS 5-5-5, I'm sure it's compatible). It's on the third pass and hasn't found anything. My roommate gave me a boot CD with a zillion different programs on it, including memory tests, so I'm going to run every one of those and hope for the best.

It's funny how it'll be running fine for up to half an hour, then suddenly freeze without any program changes. I've checked the Task Manager and it doesn't seem to change much...