Hi!

I'm hoping is not related to a dying battery.

If it is, that is far from being the end of the world. The Deskpro EN
family all use CR2032 batteries. You can buy one for "a few quid"
almost anywhere. You don't need a special computer-approved type of
battery--any good quality CR2032 from a reputable name in batteries
will do.

You might even be able to pluck a good one off of a dead motherboard
from something else if need be. Try not to touch the battery too much
when you install it. Skin oils are said to cause erosion of the
battery casing.

The battery may not be dead, but I'll bet it's close. Typically,
though, the clock starts slipping before the BIOS settings are lost.
The average lifetime of these batteries is about 5 years.

I didn't get a Windows 2000 CD with this machine so
hopefully wiping the hard drive it isn't going to be
what helps, though I do have a Windows 98 CD if the
worst comes to the worst.

I am sure you could buy a secondhand copy of Windows 2000 pretty
cheaply from a reputable seller.

The company should have spotted this, it's annoying.
If it is the battery, can I replace it myself, and
what will that cost?

If they really tested the system, yes. Oftentimes, these refurbishers
are very busy people who only have time to do a "power on test" and
call the machine good if it boots up--or in some cases, if it does
anything at all and doesn't produce too much smoke when plugged in.

The battery is socketed, you can easily remove it.

William