If you have the disk with your drivers that cam with your PC, they are on that, if not, go to the manufacturer's website and they can be downloaded. I know I always have to reinstall them, its just part of a new installation.
I have a tool that creates driver backups so that I can simply do a "restore" on a new OS and they are all back to normal again. You can also create a custom built of Windows with them pre-installed, but I've only done that once, I like to due them manually for some reason.