Having read through all the postings, I think I can add quite a few more, first, there is not many on the list of free programs for photograph handling yet, so here goes-
The one that nearly everyone into photo manipulation recommends is Irfanview from here-
IrfanView - Official Homepage - one of the most popular viewers worldwide
Next in line is PhotoFiltre this is of French origins but the English version is superb, easy to use and as good as some that can cost the old arm and leg, from here-
http://www.photofiltre.com
There are others, and most will know of the Adobe and Google basic editing suites to name a few, but they are just basic stuff not much better than windows own.
Next comes a long list of Music handling and writing programs, well me being a musician what do you expect?
First is a simple recording program that can convert any sound file that you can play on your computer, such as midi or video related sound tracks, and convert them to either WAV or MP3 and is called MP3 My MP3. available from here-
MP3 My MP3 Recorder - Record sounds and music to MP3 Free!
Have you got a noisy recording? would you like to clean it up? try Audacity, this is from the sourceforge site mentioned earlier and will also convert audio files to MP3 or WAV as well as one or two other useful tricks in its repertoir-
Audacity: Free Audio Editor and Recorder
Next we go straight into the complex world of music sequencers and music notation witing programs, the first in my list being the Frieve Music Studio Producer, this is the free one, they also do Music Studio Independance, which is shareware and costs $39 to buy the full licence, however both are available to download from here-
Frieve Home Page
To use this software you do need to know a lot about handling sequencers but is a very good program considering it is free, and it will also show the music from a midi file in notational form, but you cannot print it out in this the free version.
Next one is a true notation program which you can use to write those silly tadpoles on their lines, then play it back to hear your creation, it is full of its own manual which tells you everything you need to use it and is called Anvil Studio, available from here-
Anvil Studio Catalog
Unfortunately you cannot print off your music without buying the plugin, however you can create a midi file, store it somewhere you know where it is, then get this useful little program to print it for you. It is called "Notation Player" although only meant to be a player of midi files you can print the notation off from the display and can be found here-
Notation Software, Inc. -- Software for everyday musicians
You may have to search the site fully for "Notation Player" as they don't seem that keen on giving this one away, they would much rather you try their shareware and buy it.
Next is from the stable of Finale the American company whose main product is used by musicians worldwide and rather expensive, however they do a free program called "Finale Notepad" which is meant to get you wanting all the goodies that the paid for version gives, so hence rather a basic notation writing piece of software, but still useful for those who want to learn more about music.
https://www.finalemusic.com/store/search.aspx
Look for "Notepad" and to download you will have to sign up if you realy want it, but everything is free.
I hope that is a good supply of free programs for the photographer or musician.