Update:
Hmmmmm.....Microsoft's Windows Update Server must have been having some kind of issue yesterday, cause now I'm able to get Windows Update in XP to connect and download updates for XP, what's more, it finally managed to download and install the missing Realtek HD Integrated audio driver so all the devices are working, anyway, as I said yesterday, I'm going to ditch the Digi001 and the Protools LE software I was going to install, and see if I can get my Saffire Pro40 working with the Compaq PC instead, the good thing is, I'll be able to use Reaper with the Saffire Pro40, Might even see if I can get the Sonic Foundry Acid Music DAW software installed too, I think it'll run on XP, haven't used it for quite a few years so it'll be interesting to revisit it.
Update 2:
Oops....I had a look on the Focusrite website and apparently the Saffire Pro 40 Drivers are not compatible with Windows XP, OS compatibility is only for Windows 7 through to Windows 10, so here's my dilemma, do I stick with Windows XP or do I cut to the chase and go with Windows 10 and pay $174.00 for a new product key just to get Windows 10 activated on the Compaq PC?, I really don't want to have to go through all the headaches of trying to get a Linux OS installed on a PC, been there and done it before with major frustrations (like having to download a Linux driver for my old usb wireless 4G modem just so I could get online to download said driver, don't get me started on that).
Update 3:
I decided to go ahead and try doing a fresh clean install of Windows 7 on the Compaq PC, I was feeling a bit apprehensive about it because I wasn't sure if Microsoft would let me activate it using the product key that came with my two Genuine Windows 7 DVDs, I had used it to activate Windows 7 on my main Desktop DAW PC which is now currently running Windows 10, and wouldn't you know it, I was able to successfully activate Windows 7 on the Compaq PC....what a relief, what's more, I don't need to install any device drivers, everything seems to be all working in Device Manager.
Update 4:
Oops.....now Microsoft wants me to upgrade to Windows 10....okay, I'll see if I can do so and still be able to activate it online.
Update 5:
I think I've figured out why the Compaq PC's previous owner had put it out with the rubbish, this thing has been fighting me every step of the way.