how to install multiple pythons on window

[K.S.Wong]

Hi,

I have python 2.2 that is embedded in an application and I need to work with 
other sofware/modules that require higher python version.  I have current 
installed 2.4.  I can only use environment variables to allow one of the two 
versions to work at one time (e.g. setting pythonhome for one version at one 
time!).  Would someone let me know how could I allow both to work at the 
same time?

Appreciate your time!

best regards
Casey Wong