Before a computer can be upgraded to a 64-bit OS you must make sure the processor is a 64-bit processor and not a 32-bit processor. Intel and AMD both make processors that are 64-bit. Typically these processors are either dual core or quad core, allowing for pretty powerful computing capabilities. If your processor is not a dual or quad-core processor and you are not sure if it is 64-bit the best method of determining if your processor is a 64-bit processor is to look up the technical specifications for your processor.
If your processor is a 32-bit processor you’ll need to upgrade your motherboard, 64-bit CPU, and RAM before you’ll be able to get a 64-bit operating system. For most users, it would make more sense to get a new computer for upgrading all of these components and a new operating system.
Upgrading your operating system to a 64-bit operating system will require a 64-bit version of the operating system disc or install. If you’re installing Windows there are 64-bit versions of Windows XP, Vista, 7, and 8.
Microsoft Windows 7 professional and above have a 32-bit and 64-bit disc in the box. If you’ve installed a 32-bit disc of Windows but realize you have a 64-bit processor you can install the 64-bit version of Windows. However, you cannot use the Windows 7 64-bit disc to upgrade a 32-bit version of Windows 7, you’ll need to erase everything and do a new installation with the newer Windows version using the 64-bit disc.