Drivers are essential software for the functioning of a computer and it is a good idea to back them up to some external source. It can be a real pain to try to reinstall or repair Windows, only to find that some proprietary driver is missing or corrupt. Many PC manufacturers have their own drivers for crucial hardware and Windows generic drivers won’t work.
One approach is to download and use one of the driver backup programs discussed at Best Free Windows Driver Backup and Restore. Alternatively, more experienced PC users may wish to do the job themselves and here is how.
In Windows 7 all the drivers are in a few subfolders located in the system folder %SystemRoot%\System32\. Two standard protected subfolders are called “DriverStore” and “drivers”. Often there is also a third subfolder “DrvStore”. These folders can be copied to some external media for safekeeping.
In addition, you should back up the folder %systemroot%\inf\. This folder contains the driver setup information files. This folder is sometimes overlooked but drivers cannot be installed without the information it contains.
More discussion, including ways to reinstail drivers can be found at this link.