Totally agree with Raxx, no problems at all on my W7 laptop:
Win 7 Home Premium 64-bit
6GB RAM
Intel i7 2630QM 2.0 GHz processor
NVIDIA GeForce GT 540M graphics
The compatibility wizard in W7 fixes 99% of compatibility issues in about 20 seconds, and for anything this can't fix you can also run an XP virtual machine in W7 (free download from Microsoft:
www.microsoft.com/windows/virtual-pc/ ). I run old copies of Corel Draw which the W7 compatibility wizard can't handle, but they run absolutely 100% in the VM with minimal hassle.
Note on memory: Win 7 32-bit can only access up to 3GB of RAM, no matter how much is physically installed (see en.wikipedia.org/wiki/3_GB_barrier ). The main things that will slow Anim8or down are a slow (or busy) CPU and insufficient memory. My best suggestion is to aim for 6GB+ of RAM, W7 64-bit so you can actually use all this memory, and a Core CPU (i3, i5 or i7).
It should be noted also that Anim8or is not capable of multi-thread rendering, so don't expect miracles, but you can run multiple instances of Anim8or, each rendering different frames. A quick test with two concurrent Anim8or sessions, both rendering, showed 25% CPU usage, so in theory you might be able to render with 8 threads, just in a kinda manual way.