My Windows 7 Ultimate used to have access to the 'Switch User' feature but at some point over the past few weeks this feature is visable on the start menus but is greyed out and cannot be selected at ctrl-alt-del or in start menu. Can anyone tell me how to re-enable this feature. Thanks

Read this, see if it helps: How to Disable “Switch User” Option in Windows Vista and 7? Just do the reverse of what it says.Rich Why can't I be different and original like everybody else? - Vivian Stanshal

Hi Thanks for the link above. Strangely the Hide entry points for Fast User Switching" option was set as Not Configured. and HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System - HideFastUserSwitching was already set to 0. As you suggested I sort of worked backwards using the info in the link you provided and set Hide entry points for Fast User Switching" option to Disabled and that seems to have done the trick as I have access now to Fast User Switching again. Thanks