I'm running Windows XP Home SP3.
Graphics card: NVidia GeForce GTS450.
Blender 2.63 runs just fine.
When I try to run 2.64 or 2.64a, I get the following message:
This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.
No .blend file is necessary. It crashes on start up.