Help in removing csrss.exe Malware

My computer has been doing a lot of strange things - freezing up a lot. I found "csrss.exe" on the Task Manager; when I right click on it and then click on "File Location" it does nothing (nothing shows up. Also there is no user name or description listed with it. I was told it is malware. Ran Malwarebytes, but csrss.exe is still there. Now what do I do?
I have an HP Pavillion Slimline s5713 with WIN7 Home Premium,SP1, version 6.1
(and IE8)

I went to Malwarebytes.com and had someone start to help me. He had me run "Hitman Pro" which found "3 threats". I posted the results but never got a another reply. Found out this person was banned from forums the next day! I still have the log from the Hitman Pro program.