Here is a short list of in my experience the most important steps you can take to keep your computer and your data safe. have I have added e few remarks for clarification.
- Update your softwareNot only Windows but all other regularly used programs as well;
for a Windows PC this includes (but is not limited to)
Adobe Flash (beware of fake download sites!)
Java (if installed at all; mostly Java is not needed at all!)
- Back-up to an external hard driveDone regularly and correctly this currently is the only protection against ransomware viruses!
- Use a password managerFor single machines see Keepass, for more than one machine see LastPass
- Use a unique password for every accountEverybody has many, many accounts; you need a password manager!
- Use random passwordsEasily done only with a password manager!
- Turn on two-step verification everywhere you canIf you have a cell phone that you really use, otherwise it's useless.
- Read and think(!) before you click."My" first commandment for safe computing.
- Enable full-disk encryptionOn a single home computer? Only protects your data when the machine gets stolen.
- Put a six-digit PIN on your phone and set the phone to wipe it's contents if the PIN is guessed wrongly too many times.