USB 1 & DVD-R on win 98??

A friend wants to backup his laptop onto DVD.
It’s Win 98 & has two USB 1.1 ports & no firewire (please don’t suggest he upgrades/buys a new laptop…)

He’s been looking at external USB DVD writers, which are AFAIK USB2.
I know most USB 2 devices work on USB 1, but will the bus speed/write speed be enough for this to work?

What if he was writing from an external USB hard disk? I believe that 2 ports share the bandwidth, so read/write speeds would be halved, would the writer still work or would he be making lots of coasters?

Suggest he upgrade his laptop? Not me! But I’m the guy who had to explain the virtues of my Tandy Model 100 to a co-worker this morning.

If I understand it correctly, and this is why I bought an internal CD writer for my Win 98 machine, external drives that hook to USB 1.1 ports are limited to 4X speed. Not a lot compared to what the same drive on a USB 2.0 port can do but reasonable enough for backing up a system. If a music CD plays in 80 minutes at 4X speed that CD could be written in 20 minutes. He won’t want to watch it burn but that’s 700MB being backed up.

What about DVD writers? Does anyone know of any DVD writers that work with USB 1 (to write DVDs, not CDs) - what about the same thing on Win98?