Windows 7 - Can't use microphone in XP mode

After opening XP Mode, can attach the microphone with the USB tab at the top, but it doesn't see the microphone in Control Panel, and so doesn't work. I had it working for another user, a while back, by changing some audio setting in a file from True to False, or the other way around, but can't remember what file. Does anybody have any idea? It's a Logitech AK5370 Microphone, if that helps. Thanks!

If anyone has the same problem, this is what I found to fix the problem.
1. Go to C:\Users\%username%\AppData\Local\Microsoft\Windows Virtual PC\Virtual Machines in the Windows 7 OS
2. Right click Windows XP Mode.vmc and open with Notepad
3. Find <ui_options>
Change <audio_redirect type="boolean">true</audio_redirect>
To <audio_redirect type="boolean">false</audio_redirect>

when i open the file ,my computer hangs ? is there any other way???