Crikey DB thats a hell of a lot of data. You don't need to back up programs such as Widows, Office, Picasa etc, just the information they contain such as pics, documents and the such. No point in backing up these programs as they need to be installed, can't just copy over.
Xp has a handy backup tool in all programs, accessories, system tools, file and settings transfer wizard.:)
If your ext HDD is failing 'delayed write' try checking leads and if it's a non ext powered USB version try dual USB cable, or ext power, as it may need more power than 1 USB port can supply. Definitely don't use via hub. If nothing important on it try re-formatting.:)
As a general observation. It's not a good idea to rely on non 'permanent' media such as USB keys or ext HDD's to backup important data. They are designed to transport data not as a relable backup. eg. HDD's have moving parts, it's not a matter of will they fail but when will they fail.
Hope some of this helps.
Deano:)

