There's a free multitrack recording program called Kristal (search on Google) that's easy to use. I don't think it does MIDI but it's fine for recording audio tracks. I also downloaded ProTools Free and took advantage of Mackie's free Tracktion offer last fall. Most of the free software I use is Linux stuff, though.
If you have any interest in the Linux operating system you could go to
www.dynebolic.org and download an ISO image of dynebolic 1.4.1. It has several different recording programs (including Audacity and Ardour), drum machines, soft synths, sequencers, and streaming/multimedia software. You'd have to burn the ISO image to a CD and set your BIOS to boot from the CD drive. Takes a little while to do but it's a good introduction to free, powerful Linux audio software.
If you're looking to upgrade your soundcard, most new pro-level cards come bundled with starter versions of various software. My M-Audio soundcards include "lite" versions of Reason and Live.