The Windows 8 OS is not directly related to the RadControls for ASP.NET AJAX. What is relevant in this case is the IIS and IE that come with this version of Windows. There are not any known problems with IIS and the IE10 browser is officially supported since the Q3 2012 release of RadControls. Here
you can check a full list of the system requirements.
If you encounter any particular problems while implementing the RadControls, please contact us again.
the Telerik team
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