95 percent of hard drives are recoverable,think you need to do some work,get into safe mode n run virus and spywrae scanners,can you down load ccleaner to clean out the hd... get it here...
http://www.ccleaner.com/
if you have another pc and flash drive send ccleaner in folder in program files to it and and run it on the problem pc,you might have to bite the bullit and format the hd but that can be a good result,then look for sound problems on this forum.good luck man.