Go here and do an online scan and check to delete what it finds.
It it comes up clean, it's likely a software/hardware problem.
What is shown in the Device Manager?
Start/Control Panel/System/Hardware tab/Device Manager.
Is your sound blaster card listed there.
If so double click it to see the the status.
I am running XP with Audigy SB and every time I boot the computer up the sound is disabled and the taskbar changes from my preset blue color to grey. I have tried running many adware removers( Adaware, spybot, spysweeper, Xoftspy, Noadware and I have Mcafee 2005 all are updated. I really need help. Thanks.