Install VS 2005/2008 extensions for SharePoint on Windows XP/Vista OS
These extensions that Microsoft has created for us are simply tools for developing custom SharePoint applications which include Visual Studio project templates for Web Parts, site definitions, list definitions and a stand-alone utility program, the SharePoint Solution Generator. To be able to use them you will need to install them first. Trying to do that on a PC with Windows XP or Vista OS you won't get lucky. The first thing installation does is checking if you have Windows SharePoint Services 3.0 (WSS 3.0) installed on your machine. Because WSS can't be installed on non server OS your attempt to install the extensions will fail.
To avoid this there is only one thing that you should do and it is very easy. Just set the following key in your registry:
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Shared Tools\Web Server Extensions\12.0]
"Sharepoint"="Installed"
With this key in place the installation of both extensions (for VS 2005 and VS 2008) will continue smoothly.
The above mentioned extensions can be freely downloaded from the following URL's:
Visual Studio 2005
http://www.microsoft.com/downloads/details.aspx?familyid=3E1DCCCD-1CCA-433A-BB4D-97B96BF7AB63&displaylang=en
Visual Studio 2008
http://www.microsoft.com/downloads/details.aspx?FamilyID=7bf65b28-06e2-4e87-9bad-086e32185e68&DisplayLang=en
Have a great day!