Back story:
Standalone install in Innovator version 10 on a laptop; Windows 7 Home Premium; getting the dreaded “HTTP Error 500.21 – Internal Server error.” on login. Despite multiple attempts running aspnet_regiis.exe as specified in Installation Guide the error persists. Finally I gave up last night.
Today:
Rather than running aspnet_regiis.exe from the run command, I opened a command window and ran it in the command window. It failed and gave me a "you don't have enough administrative rights" error message. A Google searched turned up the solution:
http://forums.asp.net/t/1564305.aspx?Issue+running+aspnet_regiis+exe+i
I won't repeat the details, but the net is that Windows is trying to protect me from running programs. I made the changes as specified, rebooted and now the error is gone.
Good hunting,
Jim