Even if you have set a Windows password, thieves might still be able to access your personal files and passwords, as well as other bits of sensitive data. They could remove your Windows password (which isnt difficult) and log in to your Windows account, boot your computer into Linux (which bypasses Windows completely), or remove the hard drive and connect it to another computer.
Encrypting your drive will prevent those types of attacks. A thief could still delete your data from an encrypted drive, but the crook wouldnt be able to access it. If youre using an Ultimate or Enterprise edition of Windows Vista or later, you can use Windows BitLocker to encrypt your drive. If youre using another version or edition of Windows, check out the open-source DiskCryptor utility.
An alternative to encrypting your entire hard drive is to encrypt only your most sensitive files, such as financial reports and confidential work documents. You wont be able to protect some data (such as saved browser passwords) under this scheme, but taking this approach is better than doing nothing. If youre running a Professional, Business, Ultimate, or Enterprise edition of Windows, you can use the built-in Encrypting File System feature, which you can turn on through the properties of a file or folder. If youre on a Home edition of Windows, or if your computers do not all run the premium editions, you might turn to TrueCrypt to encrypt the files or folders you want to protect.
Wireless and mobile security
Outside of your PC, you can take other steps to keep your data safe.
Turn on Wi-Fi encryption: Most wireless routers dont turn security on by default. Enable encryption to prevent snoops from entering your network and perhaps capturing your traffic and passwords. For a home or small office, use at least WPA2-Personal (PSK) security, in which you create a password on the router and then enter it into computers and devices when connecting. For a larger business, choose WPA2-Enterprise security, which uses an authentication server or hosted service and requires users to have unique usernames and passwords.