Do the following steps in your target Windows Server 2008 x64 box.
To get the sidebar,
- From a Vista SP1 x64, copy in the content of C:\Program Files\Windows Sidebar. And place the folder in the same location.
- Run sidebar.exe /regserver
- Register (regsvr32) the 2 sidebar dlls, sbdrop.dll and wlsrvc.dll
- Clone the sidebar registry settings of the Vista box, HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Sidebar\Settings, to the target Windows Server 2008 registry.
- Run C:\Program Files\Windows Sidebar\Sidebar.exe to bring up the sidebar and set the properties to start Siderbar when Windows starts.
Now to get the Aero, assuming your graphic card is sufficient
- In Server Manager, add Desktop Experience feature.
- In Services applet, set the service, Themes, to autostart.
- In Personalization, set Theme to Windows Vista and Windows Colors and Appearance to Aero.
Then spend the next hour to add/remove all the gadgets you like/dislike, which is the fun part. After all is done, here's what a Windows Server 2008 desktop may look like.