windows help
搜索To turn Fast User Switching on or off
算了,贴这里
You must have a computer administrator account on a computer that is a
member of a workgroup or is a stand-alone computer to turn on or turn off
the User Fast User Switching feature. Fast User Switching is not available
on computers that are members of a network domain.
Open User Accounts in Control Panel.
Click Change the way users log on or off.
Do one of the following:
To specify that a user's programs remain running when another use