1. Type "regedit" in the Run From Start Menu dialog box to open the "Registry Editor".
2. Find the following key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\InetStp\PathWWWRoot
3. Change the value of this registry key from "%SystemDrive%\inetpub\wwwroot" or " \inetpub\wwwroot\" to "C:\inetpub\wwwroot". If your default website in IIS is instead stored in a different location, set the value of this registry key to that path instead.
Then install your software.