Winhttpqueryheaders() In Exclusive Download() Returned Not Found (404) May 2026

The error message typically appears in Windows log files (like SMSTS.log or ConfigMgrSetup.log ) when a system component fails to retrieve a required file from a server. Understanding the Error

Copy the URL from the log and try to access it via a web browser on the same machine.

Patches may fail to download to the WSUS server if the source file has been moved or the synchronization is corrupted. Troubleshooting Steps 1. Verify the URL and Resource Availability Check the log file for the exact URL that failed. winhttpqueryheaders() in download() returned not found (404)

Occurs when installing or updating Microsoft Endpoint Configuration Manager if the setup cannot reach the Microsoft download manifest.

Select to force a fresh copy of the files to the DP. 3. Restart or Stop Local Services The error message typically appears in Windows log

Confirm that any virtual directories (like SMS_DP_SMSPKG$ ) are correctly mapped to the right folder. 2. Re-distribute Content (for SCCM Users)

Right-click the failing package in the Configuration Manager console. Troubleshooting Steps 1

In some cases, local Windows services can interfere with the WinHTTP client. Prereq download 404 error when installing Primary Site