Proxy requirements for Windows Update


In order to use Windows Update, you must configure the proxy servers to permit HTTP RANGE requests. This article introduces the proxy requirements for Windows Update in a Windows 10 environment.

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Windows Update uses WinHttp with Partial Range requests (RFC 7233) to download updates and applications from Windows Update servers or on-premises WSUS servers. Therefore, proxy servers configured on the network must support HTTP RANGE requests.

If downloads through a proxy server fail with a 0x80d05001 DO_E_HTTP_BLOCKSIZE_MISMATCH error, or if you notice high CPU usage while updates are downloading, check the proxy configuration to permit HTTP RANGE requests to run.

You may choose to apply a rule to permit HTTP RANGE requests for the following URLs:
If you cannot permit RANGE requests, you can configure a Group Policy or MDM Policy setting that will bypass Delivery Optimization and use BITS instead.


For information about supported Group Policy and MDM settings, see DeliveryOptimization/DODownloadMode.

For more information about Delivery Optimization, see the Windows Update Delivery Optimization FAQ.

Article ID: 3175743 - Last Review: Jul 13, 2016 - Revision: 1