you don't install CAB files....the installation program does
CAB files are common to drivers Microsoft places on their os installation disks.
They are compressed files (similiar to zip) which contain several files and can even contain hundreds of driver files. You don't install a cab file. You install the device using the add new hardware program....... during hardware installation the system will automtically look for the installation disk from it's original install location. If the disk or files are not in that default location, then you must redirect it to where the driver.cab file is located. The installation will automatically look for the required file(s) within the cab file and extract from it what is needed.
If you're installing a Xerox printer then to utilize the drivers Microsoft includes with the os, you gotta install the printer using the Add Printer Wizard. When prompted for the installation disk, just redirect the installation program to examine the drive/folder where the driver.cab file is located.