Problems after Installing VS 2008 side-by-side with VS 2005

I have Visual Studio 2005 environment and decided to try VS 2008. I’ve read some articles(e.g. here) about site-by-site installation and had an impression, that making a copy of solution is enough.

NOTE: If you are using TFS, before conversion of the existing solution, obtain and install  Team Explorer Client .
VS 2005 is using TFS Source Control, but VS 2008 shows no Source Control plug-in installed.

After installing of VS 2008  I’ve copied my existing solution as MySolution2008 and opened it in Visual Studio 2008. The upgrade wizard told me that upgrade will be done in place(no backup option in the wizard) Then it showed that it converted also project files.

Then I open original Solution2005.sln in VS 2005. However wizard suggested me to upgrade to the latest version< so I wasn’t able to open existing solution in VS 2005.I’ve followed the recomendation to restore file association in VS from Tools->option->Environment->General , then click the  “Restore File Assoications” button on the dialogue.

It allowed me to open solution in 2005. However I’ve noticed that generated files (such as typed datasets and web references) were modified.The reason is that the projects were updated with extra attributes

<Project DefaultTargets=”Build” xmlns=”″ ToolsVersion=”3.5“>

and extra elements <OldToolsVersion>2.0</OldToolsVersion>.

Furthermore, for a few projects it was recommended  to open in Browse mode, because they have unsafe Includes. It also changed the path

<Import Project=”$(MSBuildExtensionsPath)MicrosoftVisualStudiov9.0WebApplicationsMicrosoft.WebApplication.targets” Condition=”” />

After fixing these changes I was able to restore my VS 2005 solution back to normal.
The similar posts , that helped me, are Moving Projects/Solutions between Orcas and Visual Studio 2005 ,
Rick Strahl‘s ‘Migrating Web Application Projects between VS 2005 and VS 2008
Multi-Targeting VS2005 and VS2008 Web Application Projects, a Gotcha!  -shows how to add conditional entries Condition=”‘$(Solutions.VSVersion)’ == ‘8.0’”/>


References to AJAX DLLs

After a few weeks after VS 2008 installation after reboot I’ve noticed that my web.config got extra
<add assembly=”System.Web.Extensions, Version=, Culture=neutral, PublicKeyToken=31BF3856AD364E35″/>
    <add assembly=”System.Core, Version=, Culture=neutral, PublicKeyToken=B77A5C561934E089″/>
    <add assembly=”System.Data.Linq, Version=, Culture=neutral, PublicKeyToken=B77A5C561934E089″/>

It caused WMIPRVSE.EXE to take 100% CPU , because of endless errors:

System.Web.HttpCompileException: error CS0433: The type ‘System.Web.UI.ScriptManager’ exists in both ‘c:WINDOWSassemblyGAC_MSILSystem.Web.Extensions3.5.0.0__31bf3856ad364e35System.Web.Extensions.dll’ and ‘c:WINDOWSassemblyGAC_MSILSystem.Web.Extensions1.0.61025.0__31bf3856ad364e35System.Web.Extensions.dll’

I had to delete the extra entries.