a question for you computer guys

just a little question for you computer wizzards
now im trying to put a 20 GB hdd in my dell dimention 8100 P4
the hdd has xp on it which i had in my old computer and has all my files and stuff
now i thought that this would be a streight forward thing to do just plug it in and away we go but i try to boot up with the hdd in and it tells me Primary harddisk drive 1 not found
secondary harddisk drive not found
error loading operating system
i've changed the jumpers all around (m) (s) (cs) but to no joy
the wierd thing is, is that i have another hdd with W2k on it and when i plug that in it works perfectly

anyways was hoping that one of you guys or girls could shine a bit of light on the matter

 

Sometimes jumpers are not that straight forward.. you have single also.. check the manufactures site for the correct jumper settings... check your cables.. swap the IDE for a know working one.. Still trying to move a loaded XP drive from Pc to PC is going to deactivate it because of hardware changes..