There are other posts complaining about Windows 7 and the inability to run Anim8or. I have one solution that would be a pain, but would work if it is windows 7 that is causing the problem. Partition your drive, or set another drive that is hooked up to your computer, on a separate partition of your main one. I don't know exactly how to do this, but there are loads of tutorials on the internet. After partitioning your drive(s) install another version of Windows (like XP) on the separate partition. Again, the internet has tutorials on doing this. Be careful, you will end up on the "dark side" of the computer doing this...
MAKE SURE YOU DON'T MESS WITH ANY FILES OR DIRECTORIES YOU ARE NOT SUPPOSED TO; YOU CAN SERIOUSLY RUIN YOUR COMPUTER!!!!!!
After all of this, you will basically have two computers in one. This is a hassel, and every time you start up you will have to decide what partition you will want on (though it may not prompt you to choose, you have to make it do so). Now, if the problem is the chipset or whatnot, this may not help, and you will have wasted hours doing this. Also, many tutorials on the internet use MS-DOS to partition, but DOS was discontinued in 2006... so you will need to find out if you can still use that DOS with Windows 7 (especially if your running 64-bit) or if you will have to get another program. Hope this helps.