What do you mean it won't install? !!1!?

With Longhorn being downloaded faster than a lightsaber wielding cat that dances on an old lady being scared by a kid surfing on the roof of his truck video, don’t forget to check out the “Oh Crap, My App Doesn’t Work Rescue Manual”.  It's lovingly called the App Compat Cookbook (quietly released to the web last month) .  This is typically the most requested doc from ISVs when they start QAing their apps.