Im going to try and explain this the best i can in the hope someone will understand me

I installed the trial version of GIF Animator 5, i think i ran it for about 9 days then i had to reboot my PC to factory settings so i downloaded it again. Everything seems exactly the same except the first time i was able to "open" an avi.video file using "GIF Animator" and take the clip i wanted but the second time i cant it just comes thru blank. Its the exact same clip i was using the first time so im not sure if im doing something wrong.
Other than this im having NO problem at all with the prog, in fact im pretty sure i will buy it if i can, or someone can, help me with this problem.
I did check FAQ and it says the prog does support avi files so im not sure what problem i have.
PLEASE HELP

Many thanks
Juls x