However, for those times you are doing development offline - maybe on a plane, maybe in a location without wifi - if you have the SDK installed, you can register this help collection with Visual Studio for offline access.
1. Open Visual Studio (you will have to open VS as an administrator in Vista).
2. In the Help menu, choose Index.
This will open Microsoft Document Explorer.
3. On the left, in the "Filtered by:" drop-down, choose "(unfiltered)" and in the "Look for field", type "Collection Manager." In the results area, below the Collection Manager heading, double click Help.
4. Below the Collections available for inclusion, check Microsoft Silverlight 2 SDK Documentation and click the "Update VSCC" button.
5. Close all instances of Visual Studio to begin the help files merge. It will take few minutes to update the collection and merge in the Silverlight help files.
6. Re-open Visual Studio. If the merge is still inprocess, a dialog will appear.
7. Reopen the Document Explorer by selecting Index from the Help menu.
8. Click the Contents Tab and look for Microsoft Silverlight 2 SDK on the left.