Try booting in 'Safe Mode' and running spybot. I'd also run adaware. It can't hurt.
Don't know what antivirus you're using, but I use AVG Free. If you're able to get to 'Safe Mode', then run you malware scanners, and antivirus software. That might help.
Kmixer.sys is supposed to be a microsloth program, but it's also been use by malware too. It looks like it's something to do with audio.
Either way, Try the 'safe mode' trick first. If that works, then you can try messing with memory. if you have more then one Dimm, then you can remove one at a time and see if the system still acts up.
Since malware can cause BSOD's and other weird system problems, you probably need to eliminate the malware first before you start tracking a possible hardware problem.
Wabbit
Whitey's Buccaneers
5th Army Air Corps