Hi,
Thank you for writing in Microsoft Communities.
Based on the issue description, it appears that you have forgotten the login password.
Please go ahead and refer the instructions mentioned from the link and later update us on the status of the issue.
How to log on to your Windows XP-based computer if you forget your password or if your password expires:
http://support.microsoft.com/kb/321305
Also Microsoft cannot help you reset, change or remove passwords for Microsoft products. For further reference check the article mentioned below.
Microsoft policy about lost or forgotten passwords
http://support.microsoft.com/default.aspx/kb/189126
Please perform these recommended steps and post back if you are still experiencing the issue.