Control Panel > Right Click Audio Device > Advanced > Untick bottom two boxes.
Can cause problems with some software though, nothing serious, just a crash, just change it back if needed, probably won't help performance too
cant find it.
im using Windows 7 maybe its different there...
Another possibility is that you might be using one sample rate in your DAWs while using another sample rate in WMP.
For example, if you're using 48k in your DAWs and decide to listen to something with WMP, your soundcard will have to stop playback in your DAW in order to start playback in WMP. This is because your soundcard has switched sample rates.
You can change the sampling rate of either your DAW or WMP to try to alleviate this problem.
Cubase - Devices/Device Setup/Your soundcard/tick release driver when application is in background.
BUT...this will allow you to play whichever is on top. You cannot play both at the same time because only one application can access the soundcard driver.
offki's advice may let you do this if you really want to but IMO it's hard enough getting a soundcard driver running efficiently with a DAW as it is, so sharing it isn't something I would recommend for everyday use.
The instructions were basically correct for Win7, I just checked....but to spell the process out exactly:
Ctrl Panel/Sound/right click or mouse select your soundcard/properties/advanced/untick the exclusive mode boxes.
Oh man i remember how much trouble this gave me back in the day.. Damn i hated it! I would open up WMP and my audio from my DAW would shut out and i couldn't fix it! Then i got an MBOX and used that as my soundcard for all media. Now I'm on to RME Good luck my friend, i know it can be annoying.