Picture software
The Gimp
If it comes to editing pictures this is for sure the best free program around. Almost no need for expensive programs like photoshop if you got this around.
Link: http://filehippo.com/download_the_gimp/
Link: http://filehippo.com/download_the_gimp/
Picasa
If you need a good freeware program to manage your huge pile of pictures there is nothing better than picasa. If you don't believe me check it out yourself.
Link: http://filehippo.com/download_picasa/
Link: http://filehippo.com/download_picasa/
Irfan View
This should be everybody's choice when it comes to picture viewers. It can show almost all commonly used picture formats and if there is one that it can't show then there is almost certainly a plug-in floating around somewhere for it. And the best is, it's totally for free. If you haven't gotten it on your computer it's your own fault...
Link: http://filehippo.com/download_irfanview/
Link: http://filehippo.com/download_irfanview/
Xnview
If you for whatever strange reason decided against Irfan View then this is the best alternative for you.
Link: http://filehippo.com/download_xnview/
Link: http://filehippo.com/download_xnview/