My pc runs Windows 7.
It all started with my google chrome running riiiiiiiidiculously slow, and something opening up windows without my permission. I found this thread http://www.tomshardware.com/forum/239851-49-simple-free-guide-removing-malware and did what it said.
I booted up in safe mode with networking. I downloaded Malwarebytes and ran a full system scan. (It found some stuff that I had it delete; also I un-installed my Avast so it wouldn't interfere.)
I downloaded and ran Combofix. (I *think* it found some stuff, I dunno, it was gibberish to me.)
I downloaded and installed ccleaner and ran it. (It fixed stuff)
I downloaded Microsoft security essentials and ran it. (because I'd been using Avast before and when I tried to re-install it, I got all kinds of error messages)
Then I re-booted and started it normal mode. It still seemed possessed so then I went back to safe mode with networking and followed the above steps AGAIN (un-installing and re-installing everything) and it found less stuff that time.
Then I went back to normal mode, and things seemed more-or-less okay, so I was like "meh, whatever, I probably killed the infection and I don't have any money to steal anyway." but now something's turning off my antivirus constantly and my computer's just acting... weird.
I noticed that my svchost.exe is using up a ton of physical memory now, too.
If you want logs or anything, I can get them for you. I can google it to figure out how to get the logs.
I can download whatever tool you want me to as well.
Thank you so much for all your help and if I'm sorry if I made things harder for you with my untutored computer tinkering. >.<