(2-part post):
It's not clear what you mean by '3 different virus softwares'. I sincerely hope that you're not actually running 3 anti-virus programs simultaneously. To do so would risk causing serious problems to your PC. (You should never have more than one anti-virus program running at any one time). If you really are running 3 anti-virus programs, disable 2 of them because they might be the cause of your problem.
I suspect that you're probably referring to anti-adware/spyware programs, such as AdAware or SpyBot. However, if you're not, the first thing to do would be to run one or more of those programs to see if there's something running in the background which is using all your PC's memory or processor time.
Next, press Ctrl-Alt-Delete and access the Task Manager. Take a look to see if there's anything running which you don't recognise. Also ensure that there's nothing labelled as 'not responding'. Use 'end task' to disable anything suspicious or which you simply don't require.