I've already written on how to install DotNetNuke on Vista/IIS 7.0 before. However, I've found a better and faster way to get it to work.
1. If this is the first time you're running a webapplication on Vista, chances are that you don't have IIS 7.0 installed. If you don't have it, go to Control Panel and then select Programs. Once there, select "Turn Windows features on or off". The screenshot below shows which should be installed as a minimum to get everything working.
Especially note that the IIS 6 features need to be installed to have debugging capabilities in Visual Studio 2005!
2. You can use the starter kit or the installation files to setup a new site. Extract to any location on your HD.
3. Since IIS 7 is more of a webserver than IIS 5.1 in Windows XP, you can create more than 1 website (in Windows XP, you can just create virtual directories).
Create a new website, I created "test" for this purpose.
Point the new site to the location where you extracted the files. Set the port to a port that's not yet used for another website (port numbers must be unique).
Now, very important: set the application pool to "Classic .net appPool". Click OK.
4.Now, still in IIS, you have to change some authentication properties. Open the Authentication window for your newly created website, and enable Windows Authentication.
5. Head back to Visual Studio, and under your project properties. Under Start Options, select "Use custom server". Enter http://localhost/<portnumber> with portnumber being the number you entered earlier.
6. Run your site and everything should now go normal.
Some remarks though... In this tutorial, it's assumed that you have installed Visual Studio 2005 SP1 and SP1 Update for Vista!
Finally, DotNetNuke working properly on Vista! This has cost me some hours, though...