A processor can be 32-bit or 64-bit depending on how the information is handled internally. An operating system can also be 32-bit or 64-bit depending on if it can use the 64-bit part of the processor. A 64-bit operating system can manage more RAM memory. In order to install a 64-bit operating system, you need a 64-bit processor. But a 32-bit operating system can be installed on a 32 or a 64-bit processor. OS X is the only consumer 64-bit operating system that does not have a 32-bit equivalent. Both Linux and Windows can be either 32-bit or 64-bit.
Go to the lower-left corner and click on the "Start" menu. Go to "Control Panel."
In the new window, scroll down and double click the "System" Icon.
You can see if your operating system is 32 or 64 bit by looking at the "System Type" line in the new window.
Open a terminal by clicking on the TV-like icon in your task bar. Both KDE and Gnome have a similar icon.
In the terminal type "uname –a" and press "Enter."
A string of information is displayed. If you have a 64-bit operating system, you will see x86_64 towards the end of that string. If you have a 32-bit operating system, you will see i386, i486, i586 or i686.
You can run 32-bit program on a 64-bit operating system but you cannot run a 64-bit program on a 32-bit operating system.
If you are planning on using more than 4GB of RAM, you will need a 64-bit operating system as 32 bit will not detect the memory beyond 4GB.