free utilities

If you are stuck with a Windows operating system, you might need some tools for basic needs, these are all free:

for brute/regexp search in .pro and .rux files: WinGrep

finding out changes in different versions of files: WinMerge
or the PSPad editor

Windirstat is quite a useful visualisation tool to clean up your drives/servers. A picture is worth a thousand words, take a look at the screenshot.
It was first developed for KDE: kdirstat

SnagIt can capture scrolling long web pages, extract text from windows, annotate images and more. Read the detailed SnagIt review.
download here
free license subscription here (thanks Eric!)

A few more tools from lifehacker

And finally, not a desktop tool per se, but quite useful to share files quick, easy and secure: