The 32-bit versions of Windows are considered to be out of date today, their key problem – is that they cannot support more than 3.25 gigabytes of memory, even if your computer has more. Lots of programs have both 32-bit and 64-bit versions. And you should install the one, which corresponds with the version of you operating system. And it’s quite easy to find out the number of bits (bit count) of your system.
Determining if your computer is 64-bit or 32-bit in Windows 7
Open “Start” menu, find “Computer” there and click it with the right mouse button. Select “Properties” in the appeared menu and in the opened window find a line “System type”.

How to find out the system bit count in Windows 8 or Windows 10
It is equally simple. Click “Start” menu with the right mouse button and choose “System” line. In the opened window, look for “System type” line.

If you have any additional questions, don’t hesitate to ask.