Having used a removable U.S.B. stick for quite a while for back up of small files, I have bought a new P.C. and find that I can't use it on the new system, I am receiving "device is not formatted do you wish to format" obviously if I do format it, I will lose everything stored there. Have tried it one several other P.Cs with the same result. the whole idea of these is to be able to transfer files from P.C to P.C.