These instructions assume that you're running Windows XP. Please let us know if you are using another operating system.
1) Start.
2) Control Panel.
3) Printers and Other Hardware. (Win2000 users use "Add/Remove Hardware")
4) Under See Also click the Add Hardware. (Next)
5) Select the "Yes, I have already connected the hardware". (Next)
6) Scroll to bottom and select "Add a new hardware device". (Next)
7) Select the "Install the hardware that I manually select from a list". (Next)
8) Select "Sound, video and game controllers". (Next)
9) Select "(Standard system devices)" then select "Audio Codecs".
10) Click "Have Disk"
11) Click "Browse"
12) Browse to c:\windows\system32 (or c:\winnt\system32 for Win2000)
13) Select the "mmdriver.inf" file. (Open)
14) Click OK to "Install from Disk".
15) If asked about Windows Logo testing just click Continue anyway.
16) Select "Microsoft GSM 6.10 Audio CODEC". (Next)
17) Select Auto-Configure, which should set both Comp and Decomp to 44100 each.
18) Click OK.
19) Click Finish.
20) Reboot
Please let us know if this fixes your problem. You may also use the technical support link in Support Staff signatures for further assistance.
Some information used from
Ventrilo Support FAQ.