Spybot Search Destroy can detect and remove spyware of different kinds from your computer. Spyware is a relatively new kind of threat that common anti-virus applications do not yet cover. If you see new toolbars in your Internet Explorer that you didn't intentionally install, if your browser crashes, or if you browser start page has changed without your knowing, you most probably have spyware. But even if you don't see anything, you may be infected, because more and more spyware is emerging that is silently tracking your surfing behaviour to create a marketing profile of you that will be sold to advertisement companies. Spybot-SD is free, so there's no harm in trying to see if something snooped into your computer, too.

Sumatra PDF is a slim PDF viewer for Windows. Sumatra has a minimalistic design but still has most of the features you need from a PDF viewer. It's small and starts up very fast. Simplicity has a higher priority than a lot of features. It's designed for portable use: it's just one file with no external dependencies so you can easily run it from external USB drive.