Windows should see some of the drivers, but depending on the hardware and the manufaturer you could have alot or only a little to do. Even if windows does install the drivers, IMHO its best practice to get the most updated copies of the drivers from the manufacturers of the hardware themselves. I tend to format roughly three to four times a year and it does keep the computer running more smooth and a good backup of everything important.
If this is your home computer don't forget to backup those favorites. I can't count the number of times I have formatted and have forgot to save my favorites...annoying to the tenth power.
