Disabled computer

The behavior described is consistent with a fake “Windows Defender” or “security alert” pop‑up triggered from the browser while using Facebook or Messenger, not with Windows actually disabling the computer.

To regain control and clear the fake alert:

1. Close the browser that shows the alert
   1. Press Ctrl + Alt + Del and select Task Manager.
   2. In Task Manager, find the web browser process (for example, Microsoft Edge, Chrome, Firefox).
   3. Select each browser process and choose End task until the browser closes.
   Alternative methods if Task Manager is not used:
   • Press Alt + F4 repeatedly to close the browser window.
   • Press Ctrl + W to close the active browser tab.
   • As a last resort, hold the power button until the PC turns off, then turn it back on.
2. After the browser is closed and the PC is back to normal
   1. Reopen the browser.
   2. Clear the browser cache and site data (history, cookies, cached files) so the malicious page does not reload from history.
   3. Avoid revisiting the same link or site that triggered the pop‑up.
3. Protect against similar scams
   • Install and enable a reputable ad blocker extension in the browser to reduce malicious or misleading ads that can cause these pop‑ups.
   • Be aware that Microsoft does not display support phone numbers in such pop‑ups and does not lock the computer and demand a call. Do not call any number shown or allow remote access.

If no phone number was called and no software was installed or permissions granted, the computer is typically not compromised; the issue is limited to the browser session.

References:

• possible virus, computer locked - Microsoft Q&A
• Windows defender scam - Microsoft Q&A
• Who do I call for support? - Microsoft Q&A
• Protect yourself from tech support scams