This is an extract from a thread about setting up sound devices - specifically it relates to Vista, but in general it applies to all current Windows OS's.
Its originator is Adobe's _durin_
You'll need to make sure that the sample rate for your input and output channels of your device match.
1. Right-click on the speaker icon in the lower-right corner of your desktop and choose Recording Devices
2. Right-click the Microphone (or desired input channel for the device) and choose Properties
3. Click the Advanced tab and verify or change the Default Format option
4. Click OK then click the Playback tab. Right-click on your default or desired output channel and choose Properties
5. Make sure the Default Format option matches what you selected for your recording channel. (You'll notice in this screenshot, my playback device is configured for 48,000Hz while my microphone was configured for 44,100Hz. These need to match.)
6. In Audition, create a new session. For best results, ensure your session sample rate matches the sample rates you selected for your decices. Audition will attempt to convert the sample rate of your recording on-the-fly to match the session sample rate, but it's always recommended to work at a single, consistent sample rate to ensure no change to the audio signal takes place.
Bob Howes added the following information to Durin's setup procedure that is Vista-specific:
The only thing to add is that you may have to do this again for future sessions--one of the pains of Vista is that it allows other software to grab the sound settings and adjust them--so if, for example, you've just watched a Youtube video with 48kHz audio, but want to record at 44.1, Windows may have left the settings at the last ones used.