Once you've formatted the system, conventionally, all the data is erased.
It's easy to retreive and install the required drivers for the system. The main drivers you'll need are the chipset drivers, graphics driver and audio driver. For most devices, windows already has the drivers, but sometimes you're required to install drivers manually.
All you need to do is take note of the system specifications, most importantly what motherboard you have, what graphics you have and what audio you have. You can then download them from the manufacturer's website.
If you don't know what your system specifications are, I'd download and install Everest Home Edition, and run it to find out your system specifications: http://www.majorgeeks.com/download.php?det=4181