At the bottom left of the Windows, click on the Search Windows icon
Enter system information and from the result, click on the System Information Desktop App
From the System Information click on the System Summary. Then check the right panel and look for the field System Type. If you see x64 meaning if you running on 64-bit Windows and if you see x86 then is a 32-bit Windows.
Another quick way to check is to go to your C:\ folder and if you are seeing a folder named Program Files (x86) then you are using 64-bit Windows.