You can try these ...
1. Make sure that the server is running.
To do this open Internet Service Manager and click Default Web Site. The Play button on the toolbar must be disabled. and pause - stop buttons enabled.
2. The home directory for your default website should be <Host Drive>:\inetpub\wwwroot
3. Goto Administrative Tools\Computer Management\Local Users and Groups\Users. Check that the any of the accounts viz... ASPNET, IUSR_<ComputerName>,IWAM_<ComputerName> are not disabled or locked. Right click on them and access the properties.
4. You can also run aspnet_regiis.exe found in the <windir>\microsoft.net\framework\<version>\ folder to set up asp.net properly on iis.
hope this works for you