Section 1: Viruses & malware
Microsoft Defender is built into Windows 11 and 10, and it can remove most infections without you buying or installing anything. Work through this section in order: check the signs, scan, use Safe Mode if the scan is blocked, then clean up the browser.
- Procedure 1.1: Is it really a virus? Symptoms to check first Which symptoms point to malware, which almost never do, and a five-minute check before you change anything.
- Procedure 1.2: Scan for and remove malware with Microsoft Defender Update Defender, run a full scan and an offline scan, act on what it finds, and confirm the PC is clean.
- Procedure 1.3: Start Windows 11 or 10 in Safe Mode Three ways into Safe Mode, for when malware or a faulty driver stops Windows or a scan from working.
- Procedure 1.4: Fix a hijacked browser: unwanted homepage, search engine and pop-ups Remove rogue extensions, notification spam and forced settings from Chrome, Edge and Firefox.
- Procedure 1.5: Ransomware: what to do in the first hour Disconnect, document, do not pay, look for a free decryptor and restore from a backup.
- Procedure 1.6: Fake security alerts: how to close them safely Recognize a scareware page, close it without clicking anything inside it, and stop it coming back.