Search for Sndvol32.exe - drag the icon to the desktop.
For slow running use the Task Manager and look at which Process is eating CPU cycles - expect to see System Idle Process well into the 90% level. A rogue process may be taking all the cycles perhaps waiting for something to happen that is not happening.
Consider using System Restore to return to a point in time before your problems began.
Good luck...
Peccavi
April 2011