How do I know if my computer is infected with a virus or other malware?

Symptoms of computer malware that affect the Internet:

·         1. You may receive the error “Internet Explorer could not display the page” when attempting to access certain websites
·         2. Your web browser (e.g., Microsoft Internet Explorer, Mozilla Firefox, Google Chrome) freezes, hangs or is unresponsive
·         3. Your web browser’s default homepage is changed
·         4. You get redirected to web pages other than the one you intended to go to
·         5. You receive numerous web-browser popup messages
·         6. Strange or unexpected toolbars appear at the top of your web browser
Malware symptoms that affect system performance:
·         1. Your computer runs slower than usual
·         2. Your computer freezes, hangs or is unresponsive
·         3. There are new icons on your desktop that you do not recognize
·         4. Your computer restarts by itself (but not a restart caused by Windows Updates)
·         5. You see unusual error messages (e.g., messages saying there are missing or corrupt files folders)
·         6. You are unable to access the Control Panel, Task Manager, Registry Editor or Command Prompt.
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Symptoms of malware in email:
·       1.   You receive messages in your mailbox without a sender address or subject.
      2.  People receive spam email from your email address with a third-party email program installed