I have a PC with 2 HDD. Can I install one WinXP OS on one drive, and another WinXP OS on the other drive and have the option to boot from either one satisfactorily? Cannot find any information on this, but any help gratefully received.

Of course, no problem at all. Just install XP to the first drive. Then put the disc back in and do it all over and choose to install it to a different drive, and it should set it up properly to allow you to select which one you want to boot from.

It is called Dual Booting. Have a look around our site and you'll find it discussed multiple times.

BTW
Welcome to TechSpot

How are the drives set up - is one Master and the other Slave, or are they both configured as Master? Both drives are on the same IDE cable.

That can be seen when your computer boots up (you'll see your computer detecting drives, primary master, slave and secondary master and slave). Also it can be checked on the hard disk itself. Open your system case (remove all power cables first) and take a look at the back end of your Hard Disk, you'll notice a few jumpers (the small things on the pins). Most of the time there is a sticker printed on the hard disk which explains what jumper setting will result in what HD behaviour.

It works fine most of the time to set them both to Cable Select. That way your computer will figure out how to use them best.

Good Luck!

Also - when I put in the set-up disk it will not now boot from the disk as all. Can I force it to boot, and how do I force it to install to the slave drive?

You can select the boot drive order from BIOS settings.

To force it to the slave drive, just be sure to select that drive when installing.

force bios to boot cd rom first
leave the HD in order 0 and 1 after cdrom

not sure bout your license's keys for WXP
you may need 2
good boot manager is Acronis Disk Director
I have 5 diff OS on my server works great

Playing around with Norton's Partition Magic, I have cleverly managed to alter the size of my HDD from 120gb to 32,000mb. I have tried the WinXP set up disc but this only recognises the drive as 32,000mb. I have managed to load back a Ghost image of an earlier copy of my Windows XP, then install Norton Partition magic in a hope that I could change the size of the HDD back to 120gb, but it shows it as 32,000mb. How on earth do I get my HDD back to the full 120gb???

I would think your best bet is to have a mess around with norton partition magic. Im sure there will be an option to expand the hard drive back to 120GB.

1) Use Partition Magic to delete the partition and then establish a new partition the size of your HDD.

2) Use PM to create a small partition on the HDD, 500mb will do, and install BootMagic from the PM CD (it is not a default installation). BootMagic is a boot manager, which will run independent of Windows (that is why it is its own little partition), which you can use to manage your dual-boot setup.

3) Have your HDD's set on cable select, in the primary IDE controller, one in position 0 and one in position 1.

4) Install XP from your installation CD to the 0 HDD, reboot, and it should be assigned the drive letter C:. Repeat for the 1 HDD, reboot, and it should be assigned the drive letter D: (if it is available).

5) Through BootMagic, establish your boot preferences.

Note: Although I think it is preferable and has certain advantages, it is not an absolute necessity to use a third party boot manager, you can use WinXP to manage the dual-boot. If you eliminate everything I stated, above, concerning BootMagic, and install the two XP's as I have indicated, XP will manage the dual-boot and provide you with a boot choice screen which will appear right after the bios boot screen.