Malware or adware slowing down the computer

Symptoms

• Unexpected pop-up ads, even outside a browser
• Browser homepage or search engine changed without your input
• New toolbars or extensions you didn't install
• Fans run high or the PC feels slow even when idle
• Programs you don't recognize in Task Manager or your installed apps list

Likely causes

• CommonAdware bundled with a free downloadMany free software installers include additional unwanted programs unless you opt out during install.
• CommonA browser hijacker changing search settingsThese often come from extensions or bundled installers.
• PossibleA more serious malware infection running hidden background processesThis can consume significant resources and pose a real security risk.
• PossibleA potentially unwanted program (PUP) masquerading as a useful toolSome 'PC cleaner' or 'driver updater' tools do more harm than good.
• PossibleAn infected email attachment or download that installed silentlyUsers often don't realize they triggered the install.

What to do

1. Disconnect from the internet temporarily if you suspect active malware, to limit further damage.
2. Run a full scan with Windows Security (Windows Defender), which is built in and effective against most common threats.
3. Run a second-opinion scan with a reputable dedicated malware removal tool for anything Defender might miss.
4. Review installed programs in Settings > Apps and uninstall anything unfamiliar, especially recently added items.
5. Check your browser's extensions list and remove anything you didn't intentionally install.
6. Reset your browser's homepage and default search engine if they were changed.
7. Change important passwords (email, banking) from a different, trusted device if you suspect a serious infection.
8. Keep Windows and your antivirus updated going forward, and be cautious about what you download and install.

Tools and parts

• Windows Security (built-in)
• Reputable malware scanner

When to call a pro

If scans keep finding the same infection repeatedly, or you suspect banking/personal information was compromised, a professional can do a deeper cleanup and help you secure your accounts.

Safety