Knowing the default password would be very useful when your computer prompts you for an administrator password, or any unknown password, and you have no idea what to put!
There are a several situations in Windows where having a default password would come in handy. For example, if you don't know an administrator password but you're diagnosing a serious problem and need to access certain Windows Vista diagnostic tools.
Maybe you're trying to install a program but you're not using an admin account - a default password would certainly save the day in this case!
While there may not be a true default password for Windows Vista, there are ways to accomplish whatever you wanted to accomplish with a default password:
"I completely forgot my password to Windows Vista so I was hoping there was a default Vista password that I could use."
You don't need a default Windows Vista password if you've forgotten yours. There are several different things you can do if you forgot your Vista password and need back in to Windows.
See I Forgot My Windows Vista Password! for several ideas including using a Windows Vista password reset disk, how to successfully guess your password, and using special kinds of programs to reset or recover the password.
"I wanted the Windows Vista default password so I could get administrator access to my account. I have no idea what my Vista admin password is."
At least one user on every Windows Vista PC should have administrator access. If you share your computer with someone else, ask if they have admin privileges and if they would be willing to grant them to your account or at least help you out with whatever administrator thing you're trying to do.
If you're the only person that uses this computer, and you're sure your user account is not already an administrator, see my How To Find the Administrator Password in Windows Vista for help.
Looking For Default Password Information for Another Version of Windows?
The solutions to the default password questions above are specific to the Windows Vista operating system so if you're using another, see What Is the Default Windows Password? for a discussion based on your version of Windows.