Logging off and switching between account
When you no longer need to use the computer, you can log off your account, which will close all your programs but not turn off the computer. To log off, click the Start button, click the arrow next to the Shut down button (not the button itself), and select Log off. If you have any programs with unsaved files open, you'll be prompted to save them before your account is logged off.
You don't need to log off your account every time you walk away from the computer. Many users find it more convenient to stay logged in unless they expect to be away from the computer for an extended period of time. As you're about to see, keeping an account logged in doesn't prevent other people from using their own accounts.
Switching between accounts
Although only one person can sit in front of the computer to use their account at a time, Windows 7 does allow multiple accounts to be logged in simultaneously, which is handy because it lets others use the computer while you're away from it, even if you didn't log off your account. To make the computer available for someone else to use in your absence without logging off your account, go to the Shut down menu and click Switch user.
This will keep your account running but will return the computer to the Windows 7 welcome screen so another user can log in.
Another option is to press the Windows+L, which will "lock" your account and allow someone else to log in from the welcome screen after clicking the Switch User button.
Windows 7 will allow two, three, four, or even more accounts to remain logged in at the same time. However, depending how much memory is installed in your computer (and how many programs each of the logged-in accounts has running), having too many accounts logged in at the same time may noticeably slow down the computer's performance and cause it to take a long time to switch between accounts. In addition, some programs may not work properly when multiple accounts are using them simultaneously, so you may need to close certain programs in one account before you can use them in another. (Apple iTunes is a good example.)
