I had to reinstall windows, how to i get my backed up files from extended hard drive back to my computer?

I had to reinstall windows on my computer. i have had backed up files on my extended hard drive since jan of 2010. the last known back up of all of my files was created on april 26, 2011. I'm wondering how do i move the backed up files back to my computer to restore everything?, when i open up the folders there are dated subfolders. i'm not sure if i need to move each item in the folder or if i can select all of the folders at the same time, and then send them to the D: drive, (this is my ops drive. i'm really confused. I really appreciate anyone that takes the time to reply to this, it means alot. Thanks again! Shannon