Desktop freezes / is useless on startup

Hi all, sorry if I have missed this issue somewhere else but there never seems to be a case exactly what like I am having problems with at the moment.
I have had my computer for about 1 year now and it has been working fine until today, when I turn it on it seems to load up fine, the desktop seems to load and I can move the cursor. But I cannot click on any of the icons or anything pinned to the action bar, I cannot right click for a dropdown and I can't ctrl+alt+del. I have tried using the windows 7 CD but it doesn't load anything at all.
Many thanks to anyone who can try and help me with this problem.

I seem to have found a fix but I was unable to do anything at all in safe mode either. I did a system restore and it worked fine but when I loaded it up again it did the same thing. Noticed that there was a new windows update and so I turned off automatic updates (after another system restore) and it's been running fine. My train of thought being that they will bring out a fix for it in a bit and I will update that.