On Windows desktops, to log in to workstation, you need to press Ctrl + Alt + Delete to display login dialog. Input your personal username and password and then press Enter (or click arrow-icon), after which system shows you regular desktop.
Desktop and its features
At the bottom of desktop view you can see horizontal taskbar. Taskbar contains Start-menu, Quicklaunch-toolbar, programs that are running and System tray with clock/date. You can start programs using Start-menu.
How to log out of desktop/network
To prevent others not to use your personal user account, you need to log out of workstations every time you are done with them. To log out, click Windows-icon in the lower left corner of desktop and choose “Log off”.