Problem playing music files with new Goodmans mp3...

Followed instructions to the letter to transfer music files to player. Per instructions draged and dropped files from Windows explorer to mp3 and player shows files as having transferred without any problem however on attempting to play mp3 displays "No Authority" and will not play. Have also tryed transfer of files from Windows Media. Once again the files appear on player as expected but this time when pressing play mp3 player displays "Unknown Format" and no joy playing files. My pc is Windows Me and is compatible with player and should not require driver (plug and play). I have tried reinstalling from scratch and also used the disc included for Windows 98 (not necessary) to see if any difference in result. The files I have transferred are not corrupt as they transfer and play without problem to additional mp3 player I have. Resisted the temptation to go into "my computer" and right click on mp3 icon to obtain drop down menu to then click on format in case I screw up player and warranty. Any assistance on this matter to resolve problem greatly appreciated. P.S. Goodmans technical customer assistance appear to be useless as they do not seem to answer my e-mails. The term "BUYER BEWARE" springs to mind !!

Many Thanks : SOLIDAIR.