Audio Configuration/Hardware????

Hi, I am looking for some urgent help. I am using Windows XP with Windows Media Player 11 and iTunes. Everything was working fine until yesterday night when I turned off the system but today morning when I booted it again I found that some applications like Windows Movie Maker, iTunes, and Windows Media Player are not working at all. Whenevr I try running any of these programs, I use to get an error message saying:

"Windows Movie Maker cannot be used because the required audio hardware cannot be found on your computer."

Don’t know what happened suddenly. I rechecked all connections and all seems to be plugged in properly. I checked device manager under audio devices and they Device is Functioning properly. Do you guys have any idea what could be wrong?

Please help.

What is the Make/Model of your soundcard? I will suggest you to better once delete the sound card software, then delete the sound card from device manager and reboot the system. After restart Windows will automatically scan for hardware changes and re-install soundcard plus its proper drivers. Once completed you can install your software again. Now see if everything is working fine.

ok i accidentally uninstalled my windows audio configuration thing because i didn't know what it was and i needed to free up space on my computer. i've tried system restore to an earlier date and that did nothing. the only cd-roms i can find are the start up for Windows 98, Compaq quickrestore and Cosmi. i have no clue what they do and how to do it. i've been to the website with all the downloadable soundcards but every time i click on one it asks for the time of the system or computer i'm using. i have no clue about that either. i just know i have this box thing in front of me that connects to Microsoft Word, iTunes and the web.
so some help would be useful.
it's Windows 98. on the monitor it says Likom. on the rectangle thing that has the Start/Reset button it says ZIP and a bunch of numbers.