Hello and Welcome to Windows7forums!
Glad to have ya on board..
This doesn't sound too bad.. sounds like a driver issue to me.. Ok, so first off, which build of Windows 7 did you install? Windows 7 Beta Build 7000 is the one that was released to the general public.. That is the one most SHOULD still be using..
Some are using the \"daily/interim\" builds (ex: 7022, 7057, 7068, 7070).. those are fine but they are not ment to be released to the general public and as such can cause more problems than their worth for some people.. So if your using one of those daily builds than it may be the cause of the problem. But we'll give it the benefit of the doubt first and see if we can get you up and running without having to reinstall Win 7..
Secondly, did you do a clean install (as in format the HDD first then install Win 7) or did you do an upgrade over top of a previous Windows OS?
What I would suggest doing first is going into Device Manager and see if there are any little yellow exclamation marks beside any of your pc's hardware.. If there is then that means there's a driver missing or one needs to be updated. If there's not then that means all your pc's hardware drivers are installed BUT one may not be the proper one to be using, thus resulting in errors like the one your having.
To help a bit more, what are your pc's specs? (Just a general summary will do) Like your motherboard, gpu, sound card, etc. Also, which driver did you use for your sound card? If you just used whatever one's came through Windows Update than chances are your going to need to update them or simply use a 3rd party driver instead. Often times the one's that come through Windows Updates aren't the best drivers to use.
That's about all I can tell ya for now until I know a little bit more about your PC and which driver's you've installed.. once I know that information we can try some other solutions..