Computer freezes when I close Norton Internet Security 2011

Whenever I close NIS 2011, my computer freezes. The screen goes blank. Occasionally, part of the desktop is visible with blank boxes.

Quick scan also seems to have issues that may or may not be resolved. NIS tells me different things.

I am running WinXP Home Edition, Service pack 3.  I upgraded a few weeks ago from Norton360 (I think, 2010).

 

I am also having difficulty in sending emails now. I cannot send attachments properly.