Installed Parallels, now Bootcamp won't boot

So I have a 13" unibody MacBook Pro (2.26ghz, 4gb RAM) with Parallels Desktop 4 and OS X Leopard. I had a bootcamp install (Windows XP), and thinking that I'd be able to run select applications in OS X, but still be able to boot into bootcamp. Now, Windows will not boot. I've seen people have this problem, and the typical solution seems to be this http://kb.parallels.com/en/4672 but the problem is I simply cannot find the "clear" option under that menu. Can someone help?