I would like to switch users, however when I click: Start, Log Off, there's no "switch user", only a dalog box that asks me "Are you sure you want to log off?" How can I change it so I'm able to switch users?

Hmm strange ^^
Tried <Windows Key> + L ?

Note: To enable Fast User Switching, you must also enable the Use the Welcome screen option. This feature cannot be used if your computer is a member of a domain. To enable Fast User Switching:

Log on to the computer as an administrator.

Click Start, click Control Panel, and then click User Accounts.

Click Change the way users log on or off.

If it is not already selected, click to select the Use the Welcome screen check box.

NOTE: The Use Fast User Switching check box is unavailable until you click to select the Use the Welcome screen check box.

Click to select the Use Fast User Switching check box, and then click Apply Options. Quit the User Accounts tool.


http://support.microsoft.com/?kbid=279765