This question already has an answer here:
This question was asked several years ago at: Can ArcGIS and OSGeo4W share the same python install?, but it seems that versions have changed since then.
I currently have ArcGIS 10.0 installed (not sure when I will upgrade to 10.1) and I would like to install OSGeo4W on my computer as well. ArcGIS 10.0 installs Python 2.6.5 and OSGeo4W wants to install Python 2.7.2. Can these two packages use the same Python installation despite different versions?
Otherwise, is there an easy way to install OSGeo4W with the correct Python version and keep the two Python versions completely separate on a single computer?