If you use the Firefox browser (and if not why not?) then you’ll know all about the useful Password Manager facility, which makes logging onto protected websites a doddle, but as Propellerhead points out, it is not very secure. Anyone using your PC can access your websites and see all of your saved passwords without let or hindrance.
To protect your security you should set a password for the Password Manager and you, (and anyone else using your PC) will be asked to enter the Master password at the first attempt to log on to a password protected website. To set it up open Firefox then go to Tools > Options and select the Privacy tab.
Click Set Master Password and enter your new password and a bargraph ‘Quality Meter’ shows how secure it is likely to be, depending on length and complexity. There’s a whole website full of useful utilities, Top Tips and freeware downloads at PCTopTips