SDI doesn’t do driver backups as such. By “backup” I mean grabbing the files of installed drivers and copying them off to a safe place. In many cases, this isn’t that useful anyway, because some of the files required to perform the installation are not there to be backed up, so those drivers can’t be restored or reinstalled.
However, there is an interesting function in SDI which can sort of do something similar. But don’t think of it as a backup, think of it as a custom driver installation package.
Run SDI and enable Expert Mode. In the section, “Found in driver packs”, uncheck everything except “Current”. This gives you a list of all currently installed drivers that also exist in the driver packs. Same model, version, signature etc. SDI has a driver exactly the same as the one installed.
Click “Select All” followed by “Extract to…”. Select a destination folder and click OK. SDI will extract the drivers from it’s driver packs and write them to the destination folder. If any driver dependencies are found, those drivers are also extracted.
You now have a collection of drivers for the PC which you can store away on the machine itself or on a customer backup drive.