This tutorial will show you how to change/update/reset the password on the 'sa' account from the graphical interfaces of MSSQL Server 7.0 and 2000 or MSDE.

Start by opening the Enterprise Manager. This is usually located here:
Start -> Programs -> Microsoft SQL Server, but your software may be configured differently.

Starting with MSSQL , the SQL Server Enterprise Manager is a snap-in for the "Microsoft Management Console" (mmc.exe). Check the Microsoft documentation if you are unsure how to use this application.

Navigate to the Logins object under the Security folder on the SQL Server you wish to administer. Then, right click on the sa account and select Properties or simply double click on it. An new dialog box will open. Now, enter a new password in the Password field under the Authentication options.
All left is to click OK.