Hi,
Have you made any changes to the computer prior to this issue?
I would suggest you to try these methods and check the issue status.
Method 1:
Run the Fix it and install the Microphone.
Hardware devices are not working or are not detected in Windows.
http://support.microsoft.com/mats/hardware_device_problems/en-us
Method 2:
Set the computer to a clean boot status, disable the antivirus and install the Microphone.
Step 1:
Perform clean boot, restart the computer.
How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7.
http://support.microsoft.com/kb/929135
Note: Please go through step 7 of the Kb to keep the computer in normal startup after fixing the issue.
Step 2:
Disable antivirus software and install the update.
http://windows.microsoft.com/en-US/windows7/Disable-antivirus-software
Note: Antivirus software can help protect your computer against viruses and other security threats. In most cases, you should not disable your antivirus software. If you do have to temporarily disable it to install other software,
You can also refer to:
Update a driver for hardware that isn't working properly.
http://windows.microsoft.com/en-us/windows7/Update-a-driver-for-hardware-that-isnt-working-properly