[Tutor] running multiple versions of python

[Fowler, Trent]

The archives aren't searchable or I would have started there.  If there is a thread dealing with this, please send me there.

I am running Windows 7 and I've installed two versions of python, 3.3 and 2.7. Python 3.3 was the first version I installed and I was able to run scripts from the desktop (not the command line). I installed python 2.7 so that I could get numpy, scipy, and matplotlib down the road, but I found that all the scripts on my desktop defaulted to python 2.7. Since I coded in 3.3 this caused some issues.

I was able to fix this by right clicking the script icon, browsing programs, navigating to the python 3.3 file in my C: drive, and selecting the idle inside that directory. But then I found I wasn't able to run those scripts with python 2.7 using the exact same procedure.

Unfortunately I don't know command-line programming very much at all, and it seemed like most of what I've seen online is geared towards that as a solution. Ideally I'd like to specify which python I want to run a script from the desktop, or possibly while I'm editing the script.

If it's relevant I'm running the eric python IDE, version 5.

I'd be happy to do the work of reading something fairly technical and long (like a blog post or PDF), but it won't help me much if it isn't aimed at beginners.

Thanks in advance, 
-Trent