There are two way to check.first is you can directly check whether key contain A or not in binding like this:-. but i think this is not the better way so instead of this you can use ko.computed to check.
Check for operating system information in Windows 7. 1  Click the Start button , enter Computer in the search box, right-click Computer, and then click Properties. 2  Look under Windows edition for the version and edition of Windows that your PC is running.
Download the driver for the edition of Windows 8, 7, or Vista that runs on the computer. To identify the edition installed on the computer, see Determine whether your computer is running a 32-bit or a 64-bit edition of Windows (kb407673).n the manufacturer's site, go to the support section (or downloads section) and locate driver downloads for the exact model of the video adapter or computer. Click the link to download the driver installer.