Need a Drivers update software

Hi, I purchase and sell Laptops. Whenever I purchase a Laptop the first thing I do is usually install the operating system again so I can get rid of all the viruses and other other garbage. Is there any good software I can use to run on my Laptops instead of installing the operating system again. The other problem is that when I reinstall the operating system again some drivers are gone and installed the drivers again one by one. Is there any program available for free or for $10-$20 which I can use to scan the Laptop for missing drivers and installed the drivers through that same software. A program which I can use on multiple computers
Please Advice.