Tripplebooting a Dell Mini10V

After playing with OSX on my Netbook and being quite happy with it, i started to have a Problem: Sound is not working anymore, and the Issues with BIOS version A06 some people where talking about in the blogosphre seem to be gone. Additionally my 40GB OSX Partition is filled up. Time to fix it! Updating the BIOS is no hassle at all, at least if your Hardware-Vendor is not dumb. Unfortunately Dell seems to be one of the later ones. The BIOS release A04 (the version currently on my netbook) is a MS-DOS executeable. So you just need a bootable DOS-USB stick and you can update it like a charm. The bad part is that the BIOS release A06 is a Windows Executeable. As I don't have Windows on my Netbook I could not update my BIOS. A support call at Dell ended with the suggestion to use an external DVD-Drive boot from the shipped Windows XP CD and update the BIOS from there. But as the CD is an install CD and not a live CD this did not work. I tried booting from Network in my office (our company uses Network-Boot to setup and machines) but had no luck either. As I was pretty stuck now I decided to reinstall everything and make a tripple boot system. I will document the steps I needed to do to get things working here as I do them in the hope that it might be usefull to others.