I am going to try and explain this issue as best as i can.
operating system windows 7 64bit
issue = I have an Western Digital 500GB external Hard drive, that has over 700 AVI files on the drive. i used to be able to play the files perfectly fine with on my Windows XP service pack 2, and my windows 7 32 bit operating systems with Divx or Windows Media Player, Now that i have upgraded to Windows 7 64 bit, When i went to burn an avi file using the software of "xilisoft dvd creator" which i have used on all operating systems. the first time i went to burn the software it only burnt 3 minutes of the movie, which the movie is twilight, the second time i went to burn the movie it burn 1 hr and 31 minutes of the movie with fantastic four at the last 5 minutes, tried it one more time and the same thing happened, and no i did not have fantastic four in the burning software, so I reloaded my operating system thinking that was the issue. and when i went to play the same avi file of twilight from my external hard drive with divx i was getting the error of "unsupported format and cannot be played without installing additional Direct Show Filters" When i tried to play with windows media player 12 i got the following error "windows media player encountered a problem" I tried to burn the file as an iso image to a dvd and load it up in a windows vista lab top and I got the same errors with the same programs. I did some research and i downloaded something called fddshow filters, which now i can play the file with divx or windows media player now, so i attempted to now burn the file with Nero 10 which i bought, and used Nero Vision and when i tried to burn it i got the error of "nero vision has experienced a serious problem and must close immediately" and it happened twice, i went to burn another AVI file from the same Harddrive and did not get the error, then i did some more research and download what was called "DivFix++" but when i loaded this file to the program it said it was not an AVI file.
So with all this information given if anyone needs any more information to further help please let me know, but can anyone let me know if its just a file issue, and if so what to do, or is it a hard drive issue.