Didn't read the whole thread, did you get this fixed?
If not, it's simply a program that runs and disables input so you're stuck with that screen. Good news is it's pretty easy to remove.
Start your Windows in safe mode with networking (hit F8 before Windows Logo) , and you should be able to get in normally.
Then it's just a case of removing the suspicious file from your start up. A program called Autoruns can do this though its a bit techie (google autoruns). Or you can try some online virus scans / malware bytes like someone else said. Problem is, the file is just an executable which displays an image, none of my virus checkers caught it I just had to remove it myself.
If you are a bit lost with this, download teamviewer in safe mode with networking from
http://www.teamviewer.com/en/index.aspx, run the client and give me the number and password and I'll fix it for you, will take 2 mins. PM me and ill give you my skype/email.
Good luck.