error: Failed to access IIS metabase

Yesterday, while i was trying to browse my C# web service deployed on iis, i got this error:

Failed to access IIS metabase...

The following two commands solved my problem:

C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727>aspnet_regiis -i
Start installing ASP.NET (2.0.50727).
......................
Finished installing ASP.NET (2.0.50727).

C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727>aspnet_regiis -ga aspnet
Start granting aspnet access to the IIS metabase and other directories used by A
SP.NET.
Finished granting aspnet access to the IIS metabase and other directories used b
y ASP.NET.

the solution is from http://forums.iis.net/t/1148195.aspx