The more recent versions of Microsoft Windows support the ability to switch quickly between logged-in users. This can be a great time saver, but leaving the other users logged in will consume extra resources and can make the computer run slowly. Eventually, it could even cause applications to fail if too many resources are in use.
For home computers, this would not normally be a problem. However, for business computers or those available for public use in libraries or Internet cafes it can also present a security risk with new users potentially able to access applications left open by previous users. The good news though, is that Microsoft have made it very simple to disable Fast User Switching in Windows 10.
Edit the Registry
The Registry is a complex hierarchical store of configuration information for computer running Microsoft Windows. Editing it is not a complex operation, but doing it wrong can cause serious problems so be sure to only change the specific key that you need to.
The tool for editing the registry is RegEdit.exe, and it may prompt for elevated privileges when you run it. If it does this, click to allow. Once in RegEdit, go to the left hand side of the window, and expand the list until you locate the following Registry key:
Once there, look on the right hand side for the following value:
This should be a DWORD (32-bit) value. If it does not exist, create it by right-clicking and select New->DWORD (32-bit) from the context menu that appears. Once the value is there, set it to 1 to disable Fast User Switching and reboot the computer to bring the new setting into effect. Setting a value of 0 will enable Fast User Switching.
For computers running the Pro or Enterprise versions of Windows 10, it is possible to use the Group Policy Editor to amend the settings. Computers on corporate domains will probably already use Group Policy to set the configuration, so your network administrator will amend this setting.
To run Group Policy Editor, run Gpedit.msc, and in the left hand pane drill down to the following section:
Computer Configuration -> Administrative Templates -> System -> Logon
This will bring a selection of values into the right hand window. From these, select “Hide entry points for Fast User Switching” and double-click to edit. Set the value to Enabled and reboot the computer to bring this setting into action. Set the value to Disabled to enable Fast User Switching again.
These two methods will disable the Fast User Switching feature in Windows 10 and prevent simultaneously logon for multiple users into one computer.