I reinstalled Windows 10-64 on a new HD because my old one was dying. I reinstalled Blender 2.76 & 2.49 as I use both. I installed Python 3.whatever & 2.7.whatever. 2.76 sees python, 2.49 doesn't. I then installed python 2.6, Blender 2.49 still didn't see python. I installed both 32 & 64 bit pythons & tried both 32 & 64 bit Blender 2.49. I set the environment variables to point to the python installs, still no go. When I point to 2.6 then Blender 2.76 won't run because it wasn't the version it came with.
Before I reinstalled Windows both blenders worked w/o issue & I had python installed. I'm not sure what I could be missing. I still use 2.49 for id game moddeling because it's got exporters for all the old games, but not I can't run the exporters.