I recommend people try Moffsoft FreeCalc (1 not 2). It's a free Windows program, and its functionality is nearly identical to the on-screen calculator everyone is guaranteed to get on exam day. Becker has something just like it built in, but it was inconvenient to click to launch it each time it was needed. Moffsoft FreeCalc can be set to stay on screen with the "Always on Top" option. I recommend becoming acquainted with the memory features, because they were helpful on some of the FAR questions.
IrfanView my favorite picture viewer after Picasa went under. It's blazing fast and can even play animated gif lol. With plugins it can even open audio files.
either AntiDupl or dupeGuru for finding duplicate files, useful to weed out duplicate memes in my collection.
Moff Calculator, basically a tape calculator, pretty basic but useful for quick calculation that you need a bit more details but it'll be overkill to use Excel.
x360ce or Xbox 360 Controller Emulator, basically just turn any cheap generic controller into Xbox controller recognizable by virtually any PC games out there that support controller.
It looks terrible, but the Moffsoft FreeCalc has been one of the best pieces on unapproved software that I use almost every day: http://www.moffsoft.com/freecalc.htm
It provides the same value as a tape calculator, but on your computer and you can copy/paste the data into PDF workpapers really easily.