Can't find any way of activating it.
Is this some kind of 'April Fool' thing?
If you can't see the blank, white box on the taskbar, or have some other issue, check the FAQ (e.g. "I use Windows XP. When I open DQSD I only see the word 'Search' on my taskbar. Why?").
Did you read "What is it?" at http://www.dqsd.net/?
If you see its blank, white box in the taskbar, you can get help. Click in the box, type '?' (no quotes) and press Enter.
No April Fool's joke, it's one of the most useful tools I've ever seen, and it's free.