How to install the Mf.sys driver in Vista

The Mf.sys device driver that was included in previous versions of Windows is not installed in Vista by default. Although only a few devices now use it, if you happen to need to use one of them, your installation will fail unless you install the driver. Here's how:

Open Windows Explorer and navigate to the System32 folder in the Windows directory (you may need to first configure folder properties to show hidden and system files in Explorer's Tools | Folder Options | Views dialog box).
Locate the System32\DriverStore\FileRepository folder.
Find the Mf.inf_[hexadecimal number] folder (for example, the folder name might be Mf.inf_dcf62a9a) and double click it.
Within the folder, right click the Mf.sys file and select Copy.
Go to the System32\Drivers folder and paste the file there. Alternatively, you can right drag and copy.
In the Destination Folder Access Denied dialog box, click Continue.
In the User Account Control dialog box, click Continue.