Most of these (but not all) are free for personal use only. Please ensure you comply with their license terms.
Be CAREFUL to find and choose the free version as some links have versions that you have to buy. Free versions of some software will attempt to up-sell you to the paid version, none of those below make this compulsory but some try really hard to make you think that it is time you paid!
I prefer some (but by no means all) freeware products to the real paid for stuff!
Anti virus and other undesirable stuff( you should definitely have one and only one paid or free)
Windows 8 and 10 have included anti-virus which is now generally considered reasonably competent. You may wish to consider other free products these are thought to be better but will all to some extent attempt to sell you further sevices - non of which I would choose to use.
Firewall ( you should definitely have one and only one paid or free)
Paid anti virus products also often include a firewall so you shouldn’t add any other firewall product. Otherwise, one comes with Windows XP and later - its not great but better in later Windows versions . Your router is probably firewalled too. This is probably the best option for many people who will often just be confused by the best Firewall products. If you understand what is being asked Comodo Firewall is probably the best.
Internet content filtering
Open DNS (you don’t install this which makes it very light on your PC)
File History in control panel or Syncback Free will backup your current data and “System image backup” buried in control panel or Macrium Reflect can backup your whole system setup, programs , configuration and data.
Microsoft Office Compatible software
Libre Office is, if you avoid complex features, mostly compatible with Microsoft Word, Excel and Powerpoint
Optical Media Burning Software (CD/DVD/Bluray)
CD Burner XP allows you to save data to recordable CD, DVD & Bluray discs