Windows:

All my computers are Windows based, and I can just about remember Windows 95, 98 & XP (which I liked).
Thank goodness I bypassed Windows Millennium Edition, Vista 8 or 8.1.
I currently use Windows 7 Home Premium, and have no immediate plans to upgrade to Windows 10.

However I recently built a new PC for my daughter which had Windows 10 and I actually liked it more than I thought I would, but only because I could hide all those silly tiles telling me the weather in Timbuktu or persuading me to buy useless things from various ‘stores’.
In my opinion these are fine on a smartphone, but have no place in a ‘business’ computer.

Photoshop CS6:

There is one must-have item of software if you are going to do serious photo editing and that's Photoshop.

I started off with Photoshop Elements and a free version of Photoshop CS2.
Photoshop Elements at that time did not have layers and this is vital in editing.
So I purchased Photoshop CS4 which lasted me very well.
There were rumours that Adobe were going to force a subscription service onto users, and at the time they were doing a promotion on upgrading to Photoshop CS6, so I upgraded. This is likely to be my last version.
I don’t mind the idea of paying by subscription, but the sting in the tail is that if one stops paying the software no longer works.

One thing my friend Don taught me was that a good landscape image requires little post-processing. The more one has to edit an image the worst the original probably was, and not worth pursuing.
This is not true for astrophotography, as without extensive post-processing one wouldn’t have a final image at all.