Is it possobile to use / reference Microsoft.Web.Administration in Visual Studio on Windows XP ? I know, that is not possible to install IIS 7 on XP, but I (must) use Windows XP as a development machine.
The answer is yes since Microsoft.Web.Administration uses IIS 7.0 configuration COM objects to manage the server.
So using DCOM should do the deal.
You have to enable DCOM on the IIS 7.0 server and like ADSI administration with IIS 6, you'll need to have administrator privileges on this server...
Well technically you will not be able to, Microsoft.Web.Administration only ships with the OS (ie Windows Vista/2008, or Windows 7/2008R2). You can conceptually be able to reference it if you copy the DLL and will be able to compile, however you will NOT be able to run your application even for managing remote servers since MWA requires other objects to be locally available to work, namely a COM library that actually implements the IIS configuration system.
You will need to hack a bit to try to make it work since you will need the DCOM type libraries (ahadmin), but even if you make it work, the solution will still be considered not supported.