What disk Format is the external USB drive ? Also does the Backup
end abruptly with a error message or simply appear to stop working ?
Are you using the built-in backup facility or a 3rd-Party backup tool ?

"gomer pyle" <he@whire.net> wrote in message
news:O$V9$A3LIHA.3852@TK2MSFTNGP06.phx.gbl...
> I've tried - several times - a full backup with Windows XP to an external
> USB drive but the backup hung after backing up 20 gigs of files of about
> 27. Why? What am I doing wrong?
>