Windows 7 - Windows (7 Ultimate x64) boots into a blank screen with a cursor

I was all good working on my computer when I decided to restart my computer because "rocketdock" (a dock program) didn't open a folder and gave me the "open with" dialog instead.

Background:-
I've installed a lot of updates recently, including SP1.
The windows is customized i.e. some files are edited.
I used tune up registry cleaner, which caused a problem in Chrome, so I used a command found on the Internet, it made tons of errors (which was mentioned by the one who suggested the command) and the computer CPU was fully loaded, the command was replacing files, or something like that. When I remember the command I'll post.

PS: "Ctrl+Alt+Delete", "Ctrl+Shift+Esc", and "Ctrl+L" don't do anything.
PS2: Safe Mode loads into the same screen.

I found it, here is the full command mentioned in the above post: FOR /R C:\ %G IN (*.dll) DO "%systemroot%\system32\regsvr32.exe" /s "%G"

try a system restore and Don't use registry cleaners

I can't use system restore:-
1) I don't even think I have restore points.
2) I can't boot to safe mode.