An .AVI file could require a CODEC the supplier of the .AVI didn't tell you about. The quick workaround is to use google.com to find and install VLCPLAYER and play it there. The fix is to look up the GSPOT program to examine the .AVI and then find the missing CODEC.
When I try to play a .avi file in WM 10 all I get is sound no video. I have a Dell E1505 Duo core and XP Media Center.