Unable To Hear Sounds On Computer

i normally run on a linspire pre-loaded machine, but due to the heatsink on its way out have been using my secondary backup windows machine: http://littlurl.com/aw9rw there has been no issue for a while, however about 2 weeks going into 3 now.i've not been able to hear any sounds out of my speakers (Internet, cnn news, etc.)except if i used windows media player, cd's and any internal/preloaded sounds worked fine, as well as any 'testing'no yellow ! or errors were seen, or are seen currently.i began to muck about in the system files,the ultimate troubleshooter is an awesome program.and ended up tossing the system restore disks in.which seemed to just place another load of the os onto the hd.as a simple glance into the file system shows an owner and fred flintstone -(previous admin i was working under) besides the 'new' addition of mine.is it possible to have overlapping or multiple layers of an os on the same hd like this?i have sound only through wmp still.have downloaded and burned a copy of gparted to facilitate a clean sweep of the hd if needed to do a fresh/clean install.