NIS 2010 issues

I have NIS 2010 on my desktop running Win XP Home SP3 and on my laptop running Win 7 Home Premium 64 bit.  I find that if I go a few days without starting one or the other of my computers, live update will often not run and on occasion, NIS will not load.

 

Sometimes, I get a dialog box with a "click to fix" message that will correct the error.

 

Sometimes, the "click to fix" does not work and I have to download a specific virus definition file.

 

On occasion, I have had to remove/reinstall NIS.

 

This past weekend, NIS would not load on my laptop after being off for seven days.  Several "fixit" boxes popped up, but none of them cured the problem.  I decided to try reloading my hard drive from a system image that I had recently created.  NIS worked perfectly after that.

 

Anyone have any suggestions on how to prevent this problem.