I needed help, and because I'm an idiot, I posted on yahoo answers: How can I stop the wrong operating system from starting? - Yahoo! Answers
I followed the advice of the first guy, downloading the software from softpedia. When I opened it, there was immediately an option to alter the startup settings so I deleted vista and set windows 7 to default. Now, when I turn on thhe put, it automatically tries and fails to start vista, with no option to start 7 (meaning I can't use my computer). I've scoured the bios for something to do but can't find anything. Also, I've tried putting in the disc I used to install with, but the same messages come up, even when I say boot from CD and not the HDD! It's possible it can't read the disk but I'm not sure. So yeah...help!!