64-bit operating system and flash player

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How do I find out if I have a 64-bit operating system?
Often 32-bit operating systems are not explicitly named or called out as 32-bit systems in any place that is obvious. However, you can check the operating system on your computer while it is running:

To check your version of Windows:

1. Click the Start menu.
2. Right-click Computer (or in some cases, it says "My Computer"). 
   
   

3. Select Properties. A System Properties dialog box displays your computer information, including the operating system. If you are running 64-bit Windows, the dialog box says it. Look at the System information on Windows XP as "x64 Edition," or the System type in Windows 7 or Windows Vista:
   
   
   
   Otherwise, assume that you have a 32-bit system. 

To check your version of Mac OS: 
Mac OS 10.6 (known as "Snow Leopard") runs in either 64-bit mode or 32-bit mode, depending on the hardware in your computer. Older versions of Mac OS run in 32-bit mode. For information on how to check your version of Mac OS, see http://support.apple.com/kb/ht3696.

To check your version of Linux:
At the command line, type: uname -a and press Enter. If the output contains "64" such as x86_64 or ia64, then you’re running a 64-bit system. 

To install Flash Player on a 64-bit system, follow these instructions: Install Flash Player on a 64-bit operating system.