Two days ago my laptop got infected by the malware "Antimalware Doctor." After trying to remove it, I kept getting a BSOD with the message IRQL not less or equal. I figured it's probably some hidden rootkit and since I didn't had time to deal with it I did a fresh reformat with Windows 7. However, after a day with nothing the same BSOD came up again. Any idea what's the problem?

The technical information on my BSOD screen are as below:

***STOP: 0x000000D1 (0x93F6300C, 0x00000002, 0x00000000, 0x93CDB714)
*** OAfilt.sys - Address 93CDB714 base at 93CDA000, DateStamp 4b95aalf

I was in fact using a Creative USB sound card. I have since deleted the drivers as they weren't necessary and so far I haven't had any BSOD occurrence. Thanks!