I have been trying to get my DLC working for my copy of Fallout 3 I got during the steam sales last year during the steam sale on my old computer. I tried doing the steps on the sticky but since this is a new computer it doesn’t have the files located on any of my hard drives. Any help would be greatly appreciated

Something doesn't make sense here. Did you purchase the GOTY edition of Fallout 3 from Steam? If so, it should automatically add in the DLCs if you re-install it through them.