This is most likely the problem.
Please follow the steps below to retrieve your key and then try registering it again:
a.
Connect to your local Microsoft Store website in the
USA,
UK (for countries in the European Union),
Australia,
France,
Germany or
Canada.
b.
Sign into the store with the same ID you used when purchasing AutoCollage.
c.
Near the bottom of the page there are a few rows of links. Click on the "Account" link.
d.
You will see a page entitled "Microsoft Store Account - Purchase History." The date and time of your order of AutoCollage should be listed. In the right side of this entry,
under "Items:", you should see Microsoft Research AutoCollage 2008, along with a line which says "License:" and shows your product key.