Given the presumed origin of your OS, make sure AUTO UPDATES is 'OFF', and look here
http://www.shavlik.com/downloads.aspx for any windows updates. Shavlik NetChk™ Protect is the program you want. It does all the windows updates without the worry of the silly Genuine User crap.
PS. Don't let Win media player update for goodness sake.....chances are your sound will disapear but only on some apps, which makes it really interesting to figure out.
Mrs TJ lost her sound, but only on Paltalk. She reinstalled Paltalk. Nothing.
I reinstalled the sound drivers, removed the card physically and made windows find it again, everything but change the sound card.
Mrs. then suggested Restore back a couple of days. Looking at the restore page it showed that WMP had just updated....
Once the PC was sent back in time to the day before WMP update, MAGIC>>>