No, not at all. Just find readme.txt in the root folder of your installation CD and check version/date written at the beginnig of the file. If there is something different from:
FALLOUT: A Post-Nuclear Role-Playing Game
Readme File - 29 September 1997
Version 1.0
then disk worth trying.
Currently most of the US distributions are known. Except for the GOG version, mentioned above, and except for the one very very early disk, where game is DOS only. So, if your disk is nothing out of the ordinarity, you'll just get a result.txt, telling exact release date and version.