Fix SEC_E_UNFINISHED_CONTEXT_DELETED (0x80090333) Fast

You're seeing SEC_E_UNFINISHED_CONTEXT_DELETED (0x80090333) — maybe in Outlook, Edge, Chrome, or a corporate app. What's actually happening here is that the Windows Schannel security package started building a secure connection (TLS handshake), but something killed that connection before it finished. The system then deleted the half-built context. It's like leaving a phone call mid-dial.

Common triggers: antivirus that sniffs HTTPS traffic, a VPN that times out, or a buggy network driver. We'll go from quickest check to deeper fixes. Stop when you're good.

30-Second Fix: Toggle Your VPN or Antivirus

This sounds dumb, but it works for maybe 40% of cases. The reason step 1 works is that both VPNs and antivirus software intercept TLS handshakes. If they time out or misbehave, Schannel kills the context.

1. Disconnect your VPN — right-click its icon, disconnect, or exit the app entirely.
2. Disable your antivirus temporarily — Windows Defender is fine, but third-party ones (McAfee, Norton, Bitdefender) often break TLS. Right-click the tray icon and pick "Disable until reboot."
3. Try the operation that failed (opening Outlook, loading a website). If it works, you found the culprit.
4. Re-enable antivirus after testing. If the error comes back, add an exception for the app (e.g., Outlook.exe) in your antivirus settings.

5-Minute Fix: Clear SSL Cache and Reset Network Stack

If the simple toggle didn't work, your system might have stale cached TLS data or a corrupted network state.

Clear the SSL/TLS Cache

This is a built-in Windows tool that often gets ignored.

1. Press Win + R, type inetcpl.cpl, hit Enter.
2. Go to the Content tab.
3. Under Certificates, click Clear SSL state.
4. Click OK.

Reset Winsock and Network Stack

Open Command Prompt as Administrator — search cmd, right-click, Run as administrator. Run these five commands, one after the other:

netsh winsock reset
netsh int ip reset
ipconfig /release
ipconfig /renew
ipconfig /flushdns

After the last command, restart your PC. The reason step 3 works is that winsock reset clears any stuck network socket states that might interfere with Schannel.

15+ Minute Fix: Clean Boot to Find the Real Culprit

If you're still stuck, some background service or driver is corrupting the TLS handshake. A clean boot disables all non-Microsoft services and startup programs, letting you isolate the problem.

1. Press Win + R, type msconfig, hit Enter.
2. Go to the Services tab.
3. Check Hide all Microsoft services at the bottom.
4. Click Disable all — this kills third-party services like antivirus, VPN helpers, and driver updaters.
5. Go to the Startup tab, click Open Task Manager.
6. Disable every startup item by right-clicking and choosing Disable.
7. Close Task Manager, click OK in msconfig, and restart.

If the error is gone in clean boot, you know it's one of those disabled services. To find which one:

• Re-enable services in groups (say, 5 at a time) in msconfig, restart, test.
• When the error comes back, the last group you enabled contains the problem.
• Narrow it down one by one. Common suspects: any antivirus service, VPN service (OpenVPN, NordVPN), or proxy software like Fiddler.

If Nothing Works: Schannel Event Logs

For advanced troubleshooting, check the system event log. The error often leaves a detail in Event Viewer that points to the specific app or driver.

1. Press Win + R, type eventvwr.msc, hit Enter.
2. Expand Windows Logs > System.
3. Look for events with Source Schannel or TLS around the time the error happened.
4. Double-click an event — the Description often includes the app name (like chrome.exe or outlook.exe) and the IP address it tried to connect to.

If you see Fatal error 40 in the event, that's a TLS handshake failure from the server side — might be a misconfigured server, not your PC. In that case, try a different network (mobile hotspot) to confirm.

Real-world case: A user on Windows 11 got this error every time Outlook tried to sync Gmail. It turned out their third-party firewall (ZoneAlarm) was intercepting port 993 (IMAP over SSL) and killing the context mid-handshake. Disabling the firewall's SSL inspection in its settings fixed it.

That's it. You should have a working TLS connection now. If not, the server you're talking to might be broken — try another device on the same network to confirm.