Having some PC issues

So, I picked up this PC for my kid. Some parts were missing, but I got everything set up, gave it a good cleaning, and started prepping it for actual use. Installed Windows 8.1, Microsoft Office, Norton, HWMonitor... just the usual stuff. Anyway, HWMonitor is telling me I've got an AMD Athlon 64 3200+ processor on an ASUS GA-M55S-S3 v1 motherboard, which is what I found online too. Is that even possible?? While I was cleaning, I tried to pop the heatsink off to swap out the thermal paste and vacuum it out, but I could only get the fan loose—the actual heatsink wouldn't budge. Since temperatures seemed fine, I just left it alone so I didn't break anything. Maybe there's another clip I missed, but I couldn't find any. From what I know, you just unclip the metal tension legs holding it to the socket and it should lift right off, maybe with the CPU, but mine won't move an inch. Second issue: the CPU usage is constantly hitting 100%. It’s spinning its wheels even when I'm doing absolutely nothing. Looking at Task Manager, the biggest resource hogs are two "Google Chrome (32bit)" processes and "system interrupts." Why am I seeing two Chromes?? That's what's driving me crazy right now. Thanks for any help or ideas. Here's the specs:

Power Supply 420w
AMD Athlon 64, 2000MHz, 3200+
ASUS GA-M55S-S3 v1
4GB DDR2-800 Samsung
Nvidia GeForce 210 1GB
HD Maxtor 6 G160E0 SCSI 160GB

Is this even enough to run Windows 8, or should I just stick with Windows 7??

Chrome.exe is usually just some background process hogging memory to keep things running smooth, you can kill it if you want. The other one is probably just an update checker looking for a new version. You can disable both, but honestly, don't...

Don't touch system interrupts under any circumstances. It's vital for Windows to actually function properly.

There’s no way you have a socket 939 CPU on an AM2 board; the slots physically won't match up. You probably have an Athlon 64 3200, but there's an AM2 version of that too.
You likely couldn't get the cooler off because the thermal paste has basically turned into cement. It's a good thing you didn't force it, since people end up bending pins all the time (I've definitely been there 😬). If you really want to pull it off, you'll need fresh paste ready since the old stuff is totally dried out. Basically, you should take it off, clean the old gunk, and apply new paste. The easiest trick is to run a benchmark to heat the PC up first, then try to remove the cooler while it's still warm—just wiggle it side to side instead of pulling straight up.

That's an ancient, weak single-core processor, and modern software is pretty hungry, even a standard browser like Google Chrome. Flash and stuff like that will just freeze it up. As for having multiple processes, Google Chrome usually opens every tab in its own process to stay stable (so if one crashes, the whole thing doesn't die). It can easily show more than just a few processes running.

You can grab dual-core processors for AM2 on eBay for next to nothing, and once you swap that in, things should run a bit more normally. Even though it's probably not worth sinking money into these old rigs, you won't go broke spending maybe $5 or $6:
http://www.ebay.com/itm/AMD-Dual-Cor...item28080f831b

I didn't even realize that chip came in an AM2 version. I haven't really dug deep into Google because I kept hitting two different links, both saying it was S939, so now I'm just lost. And man, you're totally right about pulling the chip while it's still hot—definitely good advice, though I'm not really worried about doing that right now since it isn't overheating. Only thing is, I might if I swap in a different CPU later. Speaking of which, what processor should I look for given this motherboard and GPU? Just want something decent enough so a kid can play some normal games like lega movie ?? Thanks!

Even for a light game like lega Movie gama, this PC doesn't even meet the bare minimum requirements.

I guess you'd need at least a dual-core processor like an X2 5600 and maybe pick up a used graphics card for about $83.

Just ordered a new CPU on eBay, and I've got a GPU from my old rig that works perfectly fine, so I'm just gonna mash them together. Thanks for the help, everyone.
Should I stick with Win 8-icu or just roll back to 7?

You can actually fit a pretty decent processor on that board (with some caveats), which is exactly what I’d do if I were swapping mine out right now, like this one:

http://www.ebay.com/itm/AMD-Phenom-X...item3f4813343d

If you check the Gigabyte support page for that specific board, there's a full CPU list showing everything it can handle. Just a heads-up: stick to processors with low power draw, otherwise you're going to run into trouble with that power supply. Personally, I wouldn't push past a 65W TDP. This one in the link fits the bill since it has that "b" suffix at the end.

Also, you mentioned your board is Rev1, so it's likely running an older BIOS. Flash it to the latest version (you can find it on the Gigabyte site for your model) using your current processor immediately. If you don't, there's a good chance the motherboard won't even recognize the new CPU once you swap it.

As for Windows, if you grab a beefier 2 or 3-core chip and pair it with 4GB of RAM, you could probably pull off running Windows 8...

But if you already ordered that X2 4000+, I don't know... it's better than what you've got, but it's still pretty weak, honestly.

x2 4000+ is basically on par with two 3200+ units; the single-thread performance is just really weak.