You are running into an UAC issue. You don't have access to c:\inetpub although the Administrators group has access to the folder and you are part of the Administrators group. If you have UAC enabled UAC takes your Administrator privileges away however. Welcome to UAC.
Here is an easy fix. Run the following command from an elevated command prompt (right click the "command prompt" icon and select "Run as Administrator").
icacls %systemdrive%\inetpub /grant %userdomain%\%username%:(OI)(CI)(F) /grant %userdomain%\%username%:F
This command will add full access for your user account to the INETPUB directory. Now the Administrator privileges which you don't have don't matter anymore because your account and not Administrators grant you access.
Hope this helps.
Thomas Deml
Program Manager
Internet Information Services
Microsoft Corp.
http://blogs.iis.net/thomad