You should know if you're running the 32-bit or 64-bit version of Windows Vista for many reasons, but most importantly so you're sure to install the type of software and drivers created to work with your operating system.
For example, if you're running Windows Vista 64-bit and you want to update the drivers for a device, you'll need to install the 64-bit drivers designed for the hardware. 32-bit drivers won't work in the 64-bit version of Windows Vista and vise versa.
Luckily it's very easy to figure out if your copy of Windows Vista is the 32-bit or 64-bit version.
Click on the Start button and then Control Panel.
Click on the System and Maintenance link.
Note: If you're viewing the Classic View of Control Panel, you won't see this link. Just double-click on the System icon and proceed to Step 4.
In the System and Maintenance window, click on the System link.
When the System window opens, titled as View basic information about your computer, locate the System area below the oversized Windows logo.
In the System area, look for System type below the other statistics about your PC.
The System type will report either a 32-bit Operating System or a 64-bit Operating System.
Important: There is no 64-bit version of Windows Vista Starter Edition.
Now that you know if you're running Windows Vista 32-bit or Windows Vista 64-bit, you can be comfortable choosing the correct drivers and software for your computer.
Not a Windows Vista user? See Am I Running a 32-bit or 64-bit Version of Windows? for specific instructions for your version of Windows.