Reinstall Windows 10

I need to reinstall Windows 7 Professional on a Dell workstation.  I was performing my initial set up, and I messed up my password, had to step away from it, and now I can't proceed.  I am at the point where it is requesting that I have to load the drivers, but I'm stumped.  Where do I get the drivers from?  What's next?  I only have a hardware warranty, so Dell is not very helpful.