32bit Vs. 64 Bit OS

Today’s PCs come in two varieties: those running a 32-bit Operating System and those running a 64-bit operating system. The difference is the amount of information the PC’s processor can handle at any precise moment. While a computer designed for a 64-bit operating system has vastly more potential computing power, it requires fundamental changes to the way its software is designed.

The word "bit" refers to the way computers deal with information in binary, where all data is listed as a string of digits which can either be a 0 or a 1. Each of these digits is known as one bit, meaning a 32-bit processor can process 32 digits at once. Don’t confuse this with memory, which measures the total amount of information a computer can remember without needing to use a storage device such as a disk. While the figure for memory will be much bigger, a computer can’t process all of that information at once.

The software for a computer with a 32-bit processor, including operating systems such as Windows, has to be specifically written to match that processor. The same applies to 64-bit processors. Microsoft produced 32-bit and 64-bit editions of Windows XP and Vista, and will do the same for Windows 7.

In a 32-bit version of Windows, users will not be able to install and use more than about 3GB of memory. Though many 32-bit versions of Windows list a 4GB maximum memory, they are not able to address anything more than 3GB. This is due, in part, to the way your system sets up memory addresses in your computer.

A 32-bit processor is programmed to use 32 bits (hence the name) to locate each byte of memory. To determine how many addresses this gives us, we would need to take 2 (each bit can be either 0 or 1) to the 32nd power, therefore, 232 = 4,200,000,000. This means that each memory address 32 bits long can only refer to a location within this number (4.2 billion, or 4GB). Because your computer uses these memory addresses to locate all peripherals in the machine, it cannot address 4GB of memory even if it is installed

Disadvantages of 64-bit Windows 7 over 32-bit Windows 7.

• 64-bit device drivers may not be available for one or more devices in the computer.
• Device drivers must be digitally signed.
• 32-bit device drivers are not supported.
• 32-bit programs may not be fully compatible with a 64-bit operating system.
• It may be difficult to locate programs that are written specifically for a 64-bit operating system.
• Not all hardware devices may be compatible with a 64-bit version of Windows.