If you have easy_install or pip set up for Python, you can just do “easy_install pokersleuth”. It requires a 32-bit version of Python for Windows.
As an example, to compute the odds of winning when you have a pair of Jacks, your opponent has the Ace and 5 of diamonds, and the board cards are the 3 of diamonds, 5 of clubs, and 9 of diamonds:
>>> import pokersleuth
>>> pokersleuth.calculate_equity('3d5c9d', ('JJ', 'Ad5d')
The module can also be used directly from the command line:
C:\>python -m pokersleuth 3d5c9d JJ Ad5d
It supports up to 10 players and a quite extensive syntax for specifying hand ranges. Accuracy is within one percentage point with at least 99.5% probability.