The issue you are experiencing is very unusual. It would be most helpful if you could share some additional information around your setup:
What version of Windows are you using?
What versions of Visual Studio do you have installed (if any)?
As for the manual installation package, you should be able to access all product files through the following page:
RadControls for Windows Phone Version: 2011.3 1221 (Dec 21, 2011)
the Telerik team
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