Proxy troubleshooting
Ranked causes, ordered diagnostics, and a verified remedy for windows proxy authentication prompt loop - ending with a final connection check.
Quick answer
Fix: Windows keeps asking for proxy credentials. Confirm endpoint values, test with curl through the endpoint, apply the matched remedy, then re-verify the exit IP is your assigned endpoint.
Ranked causes, ordered diagnostics, and a verified remedy for windows proxy authentication prompt loop - ending with a final connection check.
Fix: Windows keeps asking for proxy credentials. Confirm endpoint values, test with curl through the endpoint, apply the matched remedy, then re-verify the exit IP is your assigned endpoint.
Likely causes
Verified remedy
Clear the stale entry in Credential Manager, set the proxy in the matching context (netsh winhttp for services), and retest.
Likely causes
Verified remedy
Disable the system proxy if unneeded, or scope rules in Proxifier-style tools to specific applications.
The action completes and the exit IP matches the endpoint.
If curl also fails, the endpoint is unhealthy: swap to a spare.
Facts last reviewed 2026-09-01.
Match the proxy context to the consumer: browsers use user settings; services use WinHTTP.
Work the diagnosis tree top to bottom, confirm endpoint values, test with curl, then run the final connection check.
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