problem after applying windows update

[eng mostafa atta]

i have laptop dell inspiron 6400, and my sound card model is SIGMA TEL HIGH
DEFINATION AUDIO CODEC
Windows Update installed a number of updates on my PC automatically .
- KB935807 for windows vista security update
- KB936357 for windows vista update
- KB933928 for windows vista update
- KB935280 for windows vista update
- KB937077 for windows vista update
- KB890830 Malicious Software Removal Tool
- KB929916 security update for Microsoft.Net framework version 2.0
- KB905866 update for Windows mail junk e-mail filter

After restart, the microphone stop working .

please advice, Thanks a lot
mostafa atta