If you installed from a back up cd or hidden partition made by the manufacturer the drivers though they may not be the latest,should already be installed by default.If you installed from a basic windows cd then you should have a driver cd supplied with either the pc [if it a major manufacturer Dell,Toshiba etc] or individual driver cds as supplied by the manufacturer of the hardware out of which you made the pc.
If you have lost the drivers then its going to take a bit of research either by looking through device manager at the hardware IDs,hit and miss with windows update or by using a driver search program.
Theres a free license offer for Everest ultimate at the link below which may help you discover the installed hardware and possible drivers.Fill in the details and check you inbox [name doesnt have to be yours and any disposable or real email will do]
First name,last name,email address
offer: http://pro.de/aktion/chip/everst_ue
downlaod program : http://download2.pro.de/action/everest_ue_4.60.exe
Any external hardware you have i.e. printers will need their drivers installing from supplied cds or downloaded from manufacturers website then installed too.