Trying to do a system scan but Norton will not open

I have Norton Internet Security 2009 installed on my laptop.  I want to do a system scan but Norton will not open.

 

Do you have any idea why?  Would it be a virus? Someone says I defo have a virus for sure but my laptop seems to be acting fine.

 

How would I find out whether I have a virus or not? Should I uninstall and reinstall Norton or will this mess everything up if I do have a virus on here?

 

I would appreciate any help on this.

 

[edit: renamed subject for clarity.]

Message Edited by Tony_Weiss on 09-10-2009 02:51 PM