Hi,
You can uninstall WAS via "Turn On or Off Windows Features"(Windows Vista) or "Server Manager->Features"(Windows Server 2008).
Actually, visual Studio comes with a built-in Web development server that enables you to build and test applications without a dependency on IIS. For more detailed information, you can refer to:
Web Servers in Visual Web Developer
http://msdn.microsoft.com/en-us/library/9d9ats98(VS.80).aspx
Since you can run them from IIS manager by coping them to wwwroot folder, this issue should not caused by IIS server. I’d suggest you get further support on ASP.NET forum. The engineers and community members there help you in a more efficient way.
Additionally, if you want to test your sites using IIS, you can refer to the walkthrough in the following article:
Using Visual Studio 2008 with IIS 7.0
http://learn.iis.net/page.aspx/387/using-visual-studio-2008-with-iis-70/