"Service Unavailable" on fresh installation of OS and IIS 6 no matter what I try

I recently installed Windows Server 2003 on a virtual machine and then added the IIS role.

(The reason for using an old OS is to make some old software work - Crystal Reports web server component)

I have not yet added any pages/apps to the website (except one very simple test html page with 'hello' paragraph tag in it before the re-installation of iis), but no matter what I try I get 'Service Unavailable' when browsing localhost or when browsing the site from outside the server.

I have tried the steps listed here - http://support.microsoft.com/?id=918041

I have tried the steps listed here - http://support.microsoft.com/kb/842493 (even though the machine is not a domain controller)

I have tried gradually giving more and more 'freedom' to the wwwroot folders to the various user/system accounts involved. No matter what I try - 'Service Unavailable'

Each time I try the site, the event viewer shows a series of warnings - "A process serving application pool 'DefaultAppPool' terminated unexpectedly. The process id was 'xxxx'. The process exit code was '0xffffffff' each with a different process id, and then "Application pool 'DefaultAppPool' is being automatically disabled due to a series of failures in the process(es) serving that application pool.

I also tried removing the IIS role, then re-adding it (but this time - without the APS.net component)

The server is fully updated.

Any ideas?

Make sure that the IUSR and ASP.NET user accounts have permissions to read the folders that the virtual directory is pointing to in the CRweb installation. You may also need to add read/write for these users on Windows\temp, if memory serves.

And make sure that the correct version of the .Net framework is selected for the application pool. These always got me back when I was using the CRweb server.