wsus error 0x8024402c proxy name could not be resolved

TL;DR

Error 0x8024402c means the Windows Update client tried to resolve its WSUS server name through a proxy and the proxy could not resolve it - internal WSUS names should normally bypass the proxy entirely. Add the WSUS server name to the WinHTTP proxy bypass list, or remove a stale proxy the client should not be using, then restart the update service and rescan. Check the machine proxy configuration, not just the browser, because the update agent uses WinHTTP.

wsus error 0x8024402c proxy name could not be resolved

Use this when

• WindowsUpdate.log shows 0x8024402c with a proxy name resolution failure for the WSUS host.
• The affected machines recently received a new proxy PAC file, proxy group policy, or VPN client.
• Browsing works, but Windows Update and other WinHTTP-based services fail to reach internal servers.

Not for this skill when

• The WSUS name fails to resolve in plain DNS for every tool on the machine. Fix the DNS record or client DNS settings.
• The proxy returns an authentication demand rather than a resolution failure. That is a proxy credentials issue.

Steps

1. Read the exact failure from WindowsUpdate.log on an affected client: confirm the error names proxy resolution and note the WSUS host name the client is using from policy. This separates a proxy bypass problem from a plain DNS problem in the first step instead of after several changes. Verify: the log confirms a proxy resolution failure and you have the exact WSUS host name in use
2. Display the current WinHTTP proxy with netsh winhttp show proxy and compare it with the browser proxy and any PAC file result for the WSUS name. Note whether a proxy is configured at all, and whether the bypass list includes the WSUS server or the local domain suffix. Verify: you can state the active WinHTTP proxy and whether the WSUS name would be sent to it
3. Add the WSUS server name, and ideally the internal domain suffix, to the WinHTTP bypass list, or reset the WinHTTP proxy to direct access on machines that should never use a proxy for internal update traffic. Import the browser proxy only if that is your documented standard and its bypass list is correct. Verify: the bypass list now includes the WSUS host, confirmed by showing the proxy configuration again
4. If group policy or a PAC file supplies the proxy, fix it at that source as well, otherwise the local change will be overwritten at the next policy refresh. Validate the PAC file returns DIRECT for the WSUS name using a PAC testing tool or a test client with only the policy applied. Verify: policy and PAC results return a direct connection for the WSUS name on a test client
5. Restart the Windows Update service, force a detect cycle, and read the fresh log. The scan should now connect directly to WSUS and either succeed or move on to a later stage with a different code, which proves the proxy path is fixed. Verify: the client completes a scan against WSUS or reports a new, later-stage result, with no new 0x8024402c entries

Why it happens

Internal WSUS traffic is meant to go directly from client to server on the LAN. When a proxy configuration without a proper bypass is pushed to clients, the update agent hands the internal server name to the proxy, and an internet-facing proxy cannot resolve internal host names, returning the failure the client logs as 0x8024402c. Browsers often mask the problem because their PAC or bypass rules differ from WinHTTP. Correcting the WinHTTP bypass and the policy source aligns the update path with the network design: internal names direct, external names through the proxy where required.

Variants and edge cases

0x8024402c after a proxy PAC change

Diff the new PAC against the old for internal suffix handling. A removed local domain rule is the usual regression, and restoring it fixes every affected service at once.

0x8024402c only on laptops off site

Off site, the internal WSUS name may be unreachable by design. Decide whether roaming clients should use Microsoft Update off site or reach WSUS through VPN, and set policy accordingly.

0x8024402c with no proxy intentionally configured

A leftover WinHTTP proxy from imaging or an old tool can persist for years. Resetting WinHTTP to direct and finding the tool that set it closes the issue.

Compatibility: Applies to WSUS clients on Windows 10, Windows 11, and Windows Server 2016 and later using WinHTTP proxy configuration or PAC files.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_vd0grY-AGeH1YslPnghNEg