After a serious infection, as this rootkit is, you should wipe the operating sytem and reinstall.
Even after an rootkit infection, you should still be able to boot into the operating system disc to reinstall, since booting up occurs outside of the Windows environment. This assumes you have such a disc. If you have an OEM made machine and have a restore partition, you need to reinstall Win 7 from that.
The drivers for optical disc drives are contained within the operating system itself. You won’t find them elsewhere. At least, not to my knowledge.
If you need to salvage data from the hard drive before formatting and reinstalling the operating system, you could use a live Linux cd for this. It should boot up and run in memory without being installed, and allow you access to the files on the hard drive. Transfer files to usb drives, or optical discs this way.