When things behave unexpectedly, many people assume their computer has been compromised by remote hackers. Most of those people are wrong.

QR codes are a nifty way to encode web addresses and other text in a way that's easy for your smartphone to decode, but they are not without risk.

You have an email address and you want the associated phone number. It's unlikely you'll find it, but there are a few things to try.

It's hard to determine whether an email address is fake.

Spam is inevitable; just don't ask for more.

Freely accessible Wi-Fi is almost everywhere, and most systems are set up to use it safely. There are a few things to pay attention to in order to stay safe.

Don't overlook backing up as part of your computer security. When the worst happens, it's your backup that will save you.

Microsoft changed the free storage allocation for Outlook.com and OneDrive.

Google deletes accounts that are inactive for two years -- including Gmail, Drive, Photos, and even YouTube content. I’ll explain what “inactive” means, how to keep your accounts safe, and why this change could erase important cultural history.

Backing up your new computer on arrival can be an important safety net. But there are degrees of what's good enough.