Finally, I'm in the process of moving onto experimenting with Linux,
What, I thought I managed to put you weeeell off Linux the other day ?!
I have just been gifted a tower PC
Ah yes that's what I advised... experiment on a spare PC, progressively.. don't wipe your main system...
with the following specs:-
- processor - AMD Phenom 9650 quad core 2.3MHz
Stop right there, that's 8088 territory, you need at least a Pentium / 586 !!
- RAM - 4Gb DIMM
That's 400MB or so, not gonna cut it either !
- hard drive -- Seagate 900Gb
That's 90GB... that should be plenty enough just to experiment...
I'm given to to understand that it has a 100% MS Office compatible office suit as well.
Well that's marketing of course...there is "OpenOffice" installed by default usually, but its import filter is never going to be 100% ... hell even MS Office is not even compatible with itself, so can't blame others can you !
... Just like MS Windows isn't even compatible with itself either... 100% is always just marketing, it just means "good enough most of the time for most of the people"... in reality, just try it and see how it goes with your own files and usage.... only real life examples can tell you how good or bad it is...
As for the choice of distro, since PCLinuxOS is already installed well have fun with that to begin with, but once you hit your first roadblock or get frustrated by this or that, might be time to install Ubuntu, simply because it's by far the most popular distro for the average joe, so has a tremendous amount of support on forums. There are also lots of Ubuntu derivatives, mainly to give you an alternative choice of desktop user interface/environment.
For example I use Xubunbu, ie Ubuntu with XFCE as a desktop environment, because it's simple like old computers used to be, no non-sense smartphone-tabletty-like interface, these drive me nuts, confuse me, waste lots of time and screen real estate. So you can choose something you like, whatever that might be.
At the end of the day all distros suck big time, because the real problems in Linux have nothing to do with the distros themselves... you can try a million different distros, it's not gonna solve anything. That's why I settled for Ubuntu, with XFCE, so that at least if I need help, I know there is a strong support in forums. Also Ubuntu has lots of money behind it, so there are actually a lot of people working full time on it, not just a couple plumbers working part time.
Also, to reduce the amount of trouble, you can go for their " LTS " ( = Long Term Support) releases, as they tend (are meant) to be more polished/tested than the regular 6 months apart releases. There is an LTS every 2 or 3 years IIRC, no more than 3 years for sure. Not much (that pertains to the end user anyway...) if anything happens in Linux land in 3 years so you won't be missing on anything don't worry.
For example I am using version 16.04, so 5 and half years out of date, 11 releases behind... but I tired the very latest the other day and after 5 minutes playing with it and seeing it was worse not better, I moved back to my 5+ year old release.
Unless you need the latest driver of something and you don't know how to retro-fit it to your current release, then of course upgrading the entire system is the easiest way to get the driver you need.
Just my two cents/pennies after 20 years using the Penguin on my desktop !
Have fun with the Penguin !