dual boot with 2 drives

[Norman Silverstone]

< Snip >
> >
> > I have looked into using XP in a virtual window and have just wasted a
> > week trying to get a piece of equipment to work which works out of the
> > box on a pure XP machine.
> >
> > I have a working drive with Ubuntu 9.10 and all my files and I have
> > other hard drives that I can use for the XP Pro installation so, please,
> > can someone tell me the best way to proceed. I accept there are
> > alternatives but at least I would then have a choice.
> 
> Fit hard disk 1, on its own. Install XP. Patch to current.

What does patch to current mean, please.
> 
> Fit hard disk 2, as secondary after HD1. Install Ubuntu 10.04. Use 3
> partitions, no more, no less: one smallish one for root, one of 2GB
> for swap, the rest for /home.
> 
> Re-fit old hard disk with Ubuntu on it as HD3. Extract whatever you
> want from your old home directory into your new one. If necessary use
> a LiveCD for this, so you can replace files that are in use.

All this seems perfectly sensible and straightforward and well within my
capabilities, thanks. However, how I will I be able to choose which
system to boot from?

Norman