Windows

My first question is why do you need / want to back up the installed drivers?

I personally prefer to install the latest drivers whenever I perform a clean installation of Windows.

In XP, Microsoft did a much better job of having up to date drivers than with previous versions of Windows.
You can have a reasonably functional PC by just installing XP and any driver updates identified when you run Windows update.

For some hardware, you will want / need to download and install the drivers from the device manufacture.

That said, there are a few software packages that claim to be able to back up your device drivers.
I have not tried any of them, so I don't know if they are worth using.

The problem with backing up installed drivers is that you need to gather a lot of information from a variety of sources.

Numerous files in the Windows folder and sub-folders.

Date from a number of .inf files.

An ever growing number of registry keys.

Then, you need to put these all back in a manner such that Windows will recognize them properly.

Chas

You have a few options but I will only mention the easiest option available. It is not free though. Look for a program called driverguide pro. It will zip up your current drivers into either a zip file of a self extracting file.