Installation Notes For Visual Studio 2008 Beta 2
At the bottom of Scott Guthrie's blog announcement of Visual Studio 2008 Beta 2, he recommended the following:
You should download and run this batch file. This takes only a few seconds to run, and fixes an issue we found earlier this week with the version policy of System.Web.Extensions.dll - which is the assembly that contains ASP.NET AJAX. If you don't run this batch file, then existing ASP.NET 2.0 projects built with ASP.NET AJAX 1.0 and VS 2005 will end up automatically picking up the new version of ASP.NET AJAX that ships in .NET 3.5 Beta2. This will work and run fine - but cause you to inadvertently introduce a .NET 3.5 dependency in the applications you build with VS 2005. Running the batch file will change the version binding policy of the new System.Web.Extensions.dll assembly and ensure that you only use the new .NET 3.5 ASP.NET AJAX version with projects that you are explicitly building for .NET 3.5.
Thus I have downloaded the batch file (disableajaxpolicy.exe):
There is more information for developers who had already installed previous versions of Orcas. However, this is all you have to do as a supplemental task to install VS 2008 for the first time.