Windows 7 logon screen is blank; I can't access my computer.

[animalkingdom]

I was trying to change my logon screen after reading that thread on another forum. I edited authui.dll, and also kept a backup of the original.

I had the original authui.dll in my System32, and the modified version on my desktop. I moved the original to my desktop and the modified to System32. Then, for some reason, I deleted the modified version and was going to move the original back to System32. Some time in between deleting the modified version and moving back the original version, I accidentally pressed Windows key+L, and locked myself out of my computer.
Now, I can't log into it. I start it up, and it starts up like usual, but the logon screen never shows up. It's just plain black. I have no way of getting into my computer.

Can any of you guys please, please help me? Some have suggested reinstall, but I really don't want to lose everything, and I also don't have a Windows 7 disc anywhere.

I'm freaking out.

 

[UsernameIssues]

........Some have suggested reinstall, but I really don't want to lose everything, and I also don't have a Windows 7 disc anywhere.

I'm freaking out.

Welcome to the Seven Forums.

Take a deep breath and relax.

You can download a Windows 7 disc from here:
Windows 7 Direct Download Links

Then try option 2 in this tutorial:
http://www.sevenforums.com/tutorials/700-system-restore.html

If that does not solve the problem - try:
http://www.sevenforums.com/tutorials/3413-repair-install.html

 

[ComputerKid]

Boot from Windows 7 DVD,
Press Shift-F10,
Type: C:
Type: cd Windows
Type: cd system32
Type: ren authui.bak (or any file name of the original authui.dll) authui.dll