some Music won't copy an others do

Well i am trying to give music back to myroomate. he had a dell and got a new gateway laptop. b4 he gave the dell away to his mom we backed up his screw music onto my computer. now i have a alot of music and he wants his screww back along with some of my other stuff. my girlfriend wants alot of my music too. but it is hard searching among 5500 songs when most of them are singles and stuff like that. now for som reason when i try to copy certain songs over they refuse to. the give me an error message saying the operation cannot be completed because one or more items can not be found. but i can copy it from one of my hd's to another but not across the network. i might just take my girlfriend's and put it in with my compueter but what am i gong to do about my roomates laptop?



i even changhed the file permisions to 777 for my music folder and all the contents. i checked.