Welcome to the forum, bigtrees
All 64-bit installations of Windows 7 come with 2 versions to run, a 32-bit version (default) and a 64-bit version (marked as such).
You can run either one, although I'd recommend sticking with the 32-bit version - simply because although the browser works great in 64-bit mode, some of the plugins you may use will not work with it yet. This is slowly changing, so at some point in the future you may want to switch over - but for now the 32-bit version will work with almost any plugin and have almost zero performance difference

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