If you have set up your system properly you will have at least two user accounts, and Administrator account, and at least one User Account both with password protection.
Remembering the passwords for multiple accounts can be difficult at the best of times, but with many people having more than one P.C. managing passwords is even more complicated.
Fortunately Microsoft have provided a simple solution for those people who wish to safeguard themselves against forgetting their Windows passwords by allowing them to create a password recovery disk (or file)
If you forget your password, you can use the created disk (or file) to gain access to the user account that created it.
Warning - Use of this disk will allow ANYONE to access the specified user account, keep the disk safe and away from the P.C. unless you need to use it.
Put the disk away somewhere safe, and if you ever forget your password in the future, the welcome screen will give you the option to use a password reset disk