When you set the TeamViewer up, it gives you an ID and password which are needed to connect to that specific computer. You write them down and then use them to connect from home to work. The ID is always the same but the password changes so everytime you quit TeamViewer, the password expires so when you launch TeamViewer, write down the password, otherwise you may not be able to connect. If you sleep your work computer and leave the TeamViewer running, the password won't change