There is a lot of very good freeware available to Home PC users.

The following is a selection of ones I have found useful.

Anti-Virus

I recommend using Windows 10 built in security

Anti-Malware

Remove Malware and Spyware with Malwarebytes or SuperantiSpyware

Text Editor

Edit text files (like NotePad) and much much more - from Fookes software.

Image Editor

Adjust your photos and add weird and wonderful effects with Photofiltre or Irfanview.

PDF reader

Foxit PDF reader is a lightweight PDF reader with a lot of functions

Windows Shortcuts

Now includes Windows 10 and IE11

I've written a short document with some useful Windows shortcuts in it.  You can view it by clicking the link. Use Adobe to print it in Booklet form (double-sided)

Adobe Reader

If you can't view the document above, you need to install the free viewer from Adobe