As I have been doing more setting up of computers of late than doing art works. So let me share some essential softwares for any machines, expecially those that need work done on them.
1. 7-zip found at http://www.7-zip.org/ - this is an amazing utility, I don't know how I could work without zipping files and uncompressing the large of files this software works with.
2. PDF Creator found at http://sourceforge.net/projects/pdfcreator/ - not to be used for professional printers, but for normal distribution of PDF via email or just saving it for future reference, this software is great.
3. CCleaner + Defraggler found at http://www.piriform.com/ - great for cleaning up the mess windows makes after itself.
4. Firefox found at http://www.mozilla.org/ - everybody knows this software, I use it because I do feel its safer online than its alternatives.
5. Google Earth + Sketchup found at http://earth.google.com/ & http://sketchup.google.com/ - a great place to play with 3D.
6. K+Lite Codecs found at http://www.codecguide.com/ - safer to pick up a codec pack than download codecs as you need it. This one seems to be the most complete one.
7. Paint.net found at http://www.getpaint.net/ - for systems that does not have photoshop but needs some of the tools.
Thats for it for now.