Server Certificate button disabled in IIS Directory Security

Due to some reason my Server Certificate button got disabled in IIS.
After some research here is the fix I got,

http://support.microsoft.com/?id=306667

Follow these steps to reregister the controls:
Click Start, click Run, and then type the following in the text box and hit enter.

Run text 1:
regsvr32 c:\windows\system32\xenroll.dll

Run text 2:
regsvr32 c:\windows\system32\inetsrv\certmap.ocx

Run text 3:
regsvr32 c:\windows\system32\inetsrv\certwiz.ocx

(where c:\windows is your OS directory)

Close the IIS Properties window, and then open the Web site properties. Verify that you can create a certificate request.