Good Morning Jengossett
You can check which version of Windows your computer has by clicking on 'start', then going to control panel, then double click on 'system'.
If you have Windows 8, then this can be accessed by swiping in from the right edge of the screen, pointing your mouse pointer to the upper-right corner of the screen, moving the mouse pointer down, and then clicking Search, and then entering System in the search box, and clicking on System.
You should then see a section called "system type", which will tell you if you have a 32bit or 64bit operating system.
If you do have a 64bit operating system, then please let us know the full error message that you are seeing with your download.
Regards