If the rest of your PC is operating correctly, I would install an expansion USB card. When the computer boots up, it should install drivers for common chipset with no problem. Though you mentioned logging in, I'm under the impression that you should still get basic USB function for keyboard and mouse.
Failing that, if you have a USB 3.0 header, you can plug a USB 2.0 device in USB 3.0 socket and the USB 3.0 and USB 2.0 run off different controllers so should hopefully give you enough love to login and restore your old drivers.
Last is the Windows disk as you mentioned as it will load drivers from the disk, though it's always messy do a system repair as sometimes it breaks more than it fixes.