Can't open NIS 2011

I cannot open NIS 2011.

 

Application Error message when closing various other programs:  Instruction "0x7c901278 referenced memory at "0x77620000. The memory could not be read. Click OK to terminate. Click CANCEL TO DEBUG.

 

If I click either, the NIS icon in tray disappears. Should I uninstall NIS and reinstall with original CD and Product Key? Is that the best fix?  Other fix you can suggest?  I am concerned that when my NIS icon in the system tray disappears, I do not have Norton protection on line.

 

Thanks,

chevyguy