Five months on and I now have a partial solution to dual booting XP and Linux - or a small step forward anyway! Having recently had, and resolved, a disk partition issue on my Windows 10 machine, by being pointed towards EaseUS partition manager (free) - See under HARDWARE - I decided to install it on my XP machine, where I used it to 'shrink' my 150GB single MBR partition down to 100GB, leaving 50GB of 'free space'.
Having done that, I had no problem then installing Linux/Ubuntu on my machine, alongside XP - Everything went smoothly and Ubuntu didn't ask me to split my formatted partition, it just installed itself using the 50GB 'free space'
So far, so good! I can now boot to either XP or Ubuntu. Unfortunately, for some reason, running/using Ubuntu is like watching paint dry - very slow, almost like slow motion; select an option and wait for 5/10 seconds before the screen display slowly fades out and the new one fades in!!)

and it would appear that there is/are software problems with Ubuntu as it doesn't always function - sometimes it freezes and informs me that there has been a software problem and do I want to report it now or later! Usually the only way out of that is to shut down the computer using to power switch, and then reboot.
As to why Ubuntu is running so very very slowly I'm not sure, but the graphics it is saying it is using is 'GALLIUM 0.4 ON NV4A', whatever that means/is. It's certainly not the graphics I have currently installed (GeForce 6200 512MB DDR2). I've not come across GALLIUM before.
Just thought I'd post an update - I'll press on (here's to another five month hiatus!) and see what, if anything, I can resolve. Now that I've 'cracked' the dual boot aspect, I suppose I could always either - re-install Ubuntu, or perhaps try Mint. I'll post again when/if I get to take another step forward!!
