right mouse click not responding

Hi there I have tried to resolve a problem with my PC using various scanners ( online & internal ) but to no avail. My problem is when I right mouse click on any folder or most desktop short cuts the curser stays with the revolving circle icon ( vista ). Then if I click again the screen goes white and shortly after a box appears asking me to wait till the program ends , close now or see if windows can solve the problem. I always have to close the program in which all the desktop icons dissapear for a short while, then return.

I can't even right click the recycle bin to empty it. I have googled for an answer, and read quite a few suggestions but none have been successful in helping me sort the problem.

I also have ran combo fix, that too did not help. As well as all that, I have also ran malwarebytes, xsoftspy and Advaced pc tweaker. Can anyone help me out in getting my pc working again or is it a case of re-instaling ? I hope not. I have also ran sfc /scannow which reported that there was no violations.

I can post a HJT log if this will help. My BitDefender program does show evey now and then that it has blocked a virus accessing my computer but lists it as unknown & the same as to it's location.

Thanks for reading.