My computer doesnt respond to anything (not even task manager)

[Humeruzz]

My computer doesnt respond to anything... (cant open task manager)
I cant even open up the windows icon tab...
I can click random stuff, but it wont open or anything.

What do i do?
I heard something about safe mode, but how do i enable that when i cant do anything?

 

[Xavier Tan Sync]

To get into the Windows Vista and Windows 7 Safe Mode, as the computer is booting press and hold your "F8 Key" which should bring up the "Windows Advanced Options Menu" as shown below. Use your arrow keys to move to "Safe Mode" and press your Enter key.