For goodness sake, login if you can! You've gotten this far!

Hopefully you have admin priviledges on your login, and then you should be able to perform a restore. They don't take long, and should fix up your PC. Also, you might want to rollback your video/directX drivers.

I'm concerned as to what you were doing upgrading DirectX, how you did it, etc. You might also need to update your graphics cards manufacturer drivers as well.

Keep us up to date, I'll be checking back on this thread.

Regards,
Double-J