Hello Please Help a while ago my windows xp sound disappeared and internet...

[Tanwen]

...sound has also gone very quiet ? if i turn my speakers up i can just about hear it. the sound works fine on windows media player, i tunes, divx etc.. i have checked everything i can think of, sound is not muted anywhere everything looks fine in sounds and audio devices in the control panel all the volume sliders are on full, i have tried changing round the cables on my speakers and that doesn't help. i don't understand why this happened to my computer in the first place as i have made any drastic changes, not reinstalled windows and no new hardware, the only thing i did play around with around the time it happened was the programs that came with my soundcard but i changed that all back so don't think it should affect it! i have checked on a load of forums but cant find anything to help!
Has anyone got any ideas? would be grateful for any help
Thanks
right i just reinstalled the sound card but now no sounds works atall!
so toally new problem now! i had to download driver from another computer as when i uninstalled it it stopped my network from working sp i copyed it on to disk and itstall it on mine. it shows up on the device manager list as it did before but now no sound atall. any ideas?