i have python 3.1 64-bit version running on my windows 7 64-bit system.
i download blender-2.5-alpha2-win64.zip from blender.org.
i unzip the contents of the ‘Release’ folder directly to c:\Blender25 (the path for blender.exe is thus c:\Blender25\blender.exe and not c:\Blender25\Release\blender.exe).
but when i double-click blender.exe (the readme says that’s all you need to do) i get the message:
“The application has failed to start because its side-by-side configuration is incorrect. Please see the application event log or use the command-line sxstrace,exe tool for more detail.”
i’m not sure how to get to the application event log or to use sxstrace.exe, so that’s where my self-diagnostics run out of steam.
p.s.: 2.49b worked fine but i also installed with the windows installer rather than from the .zip.