I figure that there must be a way for me to run python 2.6 and 2.7 on the same computer. I've got a program that requires 2.7, but ArcGIS requires 2.6. I'd like to be able to run both programs at the same time. I've installed both and in the geoprocessing settings set the default editor to C:\Python26\ArcGIS10.0\Lib\idlelib.idlepyw. Now when I right click in ArcToolbox, select edit, the IDLE 2.6 editor comes up but the script won't appear like it formerly did. I can view the script in IDLE 2.7 but that doesn't do me any good.