This is NOT a hardware related question.... You should have asked in Software, Operating system or Computer, Notebooks/Laptop PCs or Desktop PCs.
Obviously, you don't use the correct password for the user name you attempt to use.
If it's your computer, make sure that you are typing the correct password while respecting the UPPER and lower case letters.
You may also use a live DC to boot it and retreive your files.
If it's not your computer, ask the owner to give you the needed password, or create you an acount.
If it's a computer you just bought, ask the seller to give you the password. If he can't, it's a stolen computer. RETURN IT AND GET A REFUND!!! If the seller refuse, DENOUNCE him to the police.
Electro, April 2012
