Well its unlikely the store is related to running the program ...
Have you verified your installation ... The first thing is to get GameGuru running
Have you verified your installation ...A lot can happen in a month ..
Go to your steam library and right click on GameGuru...Select "properties" .....then select "local files" and finally "verify integrity of game cache"
See if that brings anything to light and fixes your issue ...
The only person ever to get all his work done by "Friday" was Robinson Crusoe..