Python 3.x is not compatible with 2.x.
If Mercurial supports 2.4 and higher, you better install python 2.6.x.
Yes, there are installers that come bundled with python.
At the command prompt, you run the following command, and if you do not get any errors, you intend to use mercurial
> hg version > hg debuginstall > hg test_mercurial > cd test_mercurial
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