I get the exact same problem, although when I run the 2 commands;
Net localgroup Users Interactive /add
Net localgroup Users "Authenticated Users" /add
I get a failure with -
system error 1378 has occurred. The specified account name is already a member of the group.
I also turned off UAC and rebooted. I still get the blue screen.
I also checked the winlogon shell and it's using explorer.exe.
All I did was upgrade the DC (my main dc) with sp1. I also put the wsus on this domains around the same time. wsus failed, so I installed it manually.
This was an old 2003 domain, but I upgraded everything, so I have 2 DC's and a separate exchange server. I can login fine using mydomain\myname but with mydomain\administrator I get a blue screen.
All I can think is this is a permissions issue somewhere. When I log in with myname, I go to remote desktop connections. I can see the administrator login fine.
Has anyone got any ideas? Or ways I can find a solution?