If you try and access OWA 2007 you may see this error
440 Login Timeout
It would appear that this error happens if the IUSR_ and / or IWAM_ accounts are disabled on the server.
Using Computer Mangement on the server, navigate to Local Users and Groups and select the disabled acount and using right click select properties
Now uncheck “Account is disabled”
Once you have done this for the IUSE and IWAM account run and IISReset
All should be back to normal!