Network Communications

Help!!!!!
Our application needs to copy a file from our local NT or 95 computer to other remote NT or 95 computers.We have used a function CopyFile which works fine while copying from an NT to NT or 95, but fails while copying from 95 to NT or 95. Another interesting aspect on 95 is that fopen returns a Network access denied or file already exists even though the mode which is passed to fopen is to overwrite the existing file. Can u help us in doing the same.
Thanking u in anticipation.