With the introduction of IIS 7.0 in windows vista number of people have been reporting problems when trying to debug their ASP.NET applications on Windows Vista with Visual Studio 2005 F5 debugging support. There are a handful of posts about trying to get this to work in various ways.
I also faced similar issues. As there are already some good articles floating on net, so instead of reinventing the wheel, I am giving below the links to those articles here. This post I am publishing for my reference only, but if you found this article then I hope this will provide you too with one stop solution to most of the issues. And if you have any good articles then please post as comment.
For me just the first link was more then enough, but for your knowledge I think every link has got some unique combination of knowledge which may help you, and save you time googling with flooded search result.