Windows 7: Difficulties with task manager

For some reason, I can't run on any programs. Not so sure why. Is it cause of a malware or something?

Plus my task manager won't open. Previously, I was ending some unecessary processes. And I think i accidentally ended 1 process which cause this problem. Whenever I press " CTRL + ALT + DEL " they'll give me a message saying

"The logon process was unable to display security and logon options when CTRL + ALT + DEL was pressed. If the operating system does not respond, press ESC or restart the compuuter by using the power switch "

I restarted my computer a number of times but it still does not help. Can some1 help me please?

At the moment, only Internet explorer works. Apps such as google chrome , media player doesn.. =(
Much appreciated!

Please post your computer specifications to give people a better understanding of your problem.

Try running chkdsk Disk Check

Boot into Safe Mode and run a full virus check with Malwarebytes Malwarebytes : Free anti-malware, anti-virus and spyware removal download

There may be some corrupt or damaged system files.

SFC /SCANNOW Command - System File Checker