32-bit processors as their name suggest use 32 bits to encode data. It simply means that the operating system and whatever program installed on the system work with data units 32 bits in length. For example, Windows 95, 98, and XP are based on the 32-bit architecture. A computer with a 32-bit processor can only allow a 32-bit version of an operating system installed. You cannot have a 32-bit processor and a 64-bit operating system on the same computer.

A 64-bit processor work with data units that are 64 bits wide. A computer with a 64-bit processor can have a 64-bit or 32-bit version of an operating system installed. However, with a 32-bit operating system, the 64-bit processor would not run at its full capability. 64-bit processors became popular in home computers in early 2000s though they have been around since the 1960’s. Windows XP, Windows 7, and Windows 8 all have 64-bit versions

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