[mat..]

Hi, I don't know a lot about malware but I have been able to remove viruses in the past. However I have this google redirect malware (windowsclick.com) and I've been working for days to try to get rid of it. I've tried researching about how to get rid of it but it's too complicated and my situation is different. This malware is known as UACd.sys but I searched for it and its no where to be found. (Im on a different computer than the affected one)
When i first noticed that google was acting up I downloaded AVG. It didn't pick anything up. I then downloaded SuperAntiSpyware but the malware stopped allowing me to open antivirus programs. Now my computer is really acting up and it freezes if you try to click things too fast or do too many things at once. (I think I've had to power off about 30 times because of freezes.) I downloaded Spyware Doctor and it picked up the malware! but you have to buy it to remove it and it doesn't tell me where the malware is hiding.
Now its in worst state ever and on startup it'll freeze within the first 5 minutes even if I don't click anything. I tried booting in safe mode but when I go to enter the username and password for the computer it says its incorrect. I dont know if this is revelant but this the computer belongs to school board. I tried just putting in administrator as the username but that didn't work. I'm totally stumped as I can't do anything without it freezing up! help pleaseee!