In order to know how many bits: 32 or 64 Windows 8, you need to hold down the Windows key (with company logo) and press X (IKS). Window opens Power User Menu (system Properties). Click on the drop-down menu System (System) and opposite the indicator System Type (system) will include your version of Windows 8. On a 32-bit system you can install both 32-and 64-bit processor, so pay attention to the last part of the string: x86 – 32bit, x64 – 64-bit.
For Windows 7 and Windows Vista, you need to open "start menu" and find the Computer (Computer). Click the right mouse button and select System (System). You will see a window with the basic features of your computer, go down to the line System Type (system), in front of which and will indicate the kind of operating system. Then click left on the button Device Manager (device Manager), locate the processors and expand the list. If you see a lot of the same points, then you have a multicore processor. Open any of them, select the Details section (Details). There will be specified the bitness of the system architecture.
To find out how many bits: 32 or 64 on Windows XP, you can use the following. Click the right mouse button on the labels on My Computer (My computer) and open the item General (common). Under System (the System) will indicate the kind of operating system. If there is no line "x64 Edition", then you have a 32-bit system architecture.