Hi noak and welcome to forums... have you ever tried Bazooka Scanner ? If not, go here:
http://www.kephyr.com/spywarescanner/Download it, install it on your system, update it and run SCAN. You'll be surprised what can it find... some very nasty things that Spybot nor Ad-Aware couldn't even smell... I use all of them, and that's best advice I can give you right now. But, again... run Bazooka and you'll see right away if you have those ugly spyware and adware files installed on your system.
Bazooka doesn't repair or clean anything, but it gives you great advices on how to manually remove those things from your PC. Some of them requires your PC to be booted in Safe Mode, because sometimes, that's the only possible way to clean them... after that, you have to run regedit and manually remove some keys left. Removing some of those spyware and adware thingies, sometimes could be very painful process, 'cause they can keep coming back... but you have to follow those advices carefully, and soon, everything will be under your control.
Cheers !