Making notes in your PC for passwords, documents and other important data is the most insecure way to store confidential data. Anyone who has access to your computer will be able to open and see those files.
Encrypting your data is very important to protect your confidential notes. This is where my favourite text encrypter comes in handy. Steganos LockNote is a freeware tool to encrypt and decrypt any text document in a simple, secure and independent way. You can unlock it anywhere with the help of a password.