How do I create an administrator's account with Windows 7? ?

I don't know what's going on with your computer, windows does not come without a working admin account. If you bought the computer new you need to call Acer support. Or take the computer back to where you bought.If they sold it to you as a new computer it isn't. If you have the OS CD that comes with most computers reinstall windows. At this time your computer has a user account with limited rights, which means you can't do anything. Can't install programs and can't change any setting in Windows.