There is a lot of very good freeware available to Home PC users.  The following is a selection of ones I have found useful.
It's essential that your computer is protected from viruses.I recommend Avast 
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)

Updated March 2019
Adobe Reader
If you can't view the document above, you need to install the free viewer from Adobe
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