Reinstalling 5.0.396

I am having some issues such as sandbox and 2 of my shields are showing no activity. This is on my computer that has Pro Anti virus. Question, if I do an install over 5.0.396 will my license still be active or what would I have to do. The reason I want to do a reinstall is because on another computer I installed the free 5.0.396 and it works just fine.  Originally I installed 5.0.377 over 4.8 then upgraded to pro anti virus.

I am using Vista 32 bit! Thanks a bunch!