Looking for a virtual drum machine a la FruityLoops but don't have the cash to by anything? Well, good news, there's Hydrogen. It's not as complex as FruityLoops of course but still you can make some nice drum loops using Ladspa effects. There's a neat mixer, a step sequencer of cource & a main sequencer to built your song. It's not perfectly stable but usable.
http://www.hydrogen-music.org/There's a windows version in the download section.
Have fun!