We are using a registry entry to connect our internal workstations to our WSUS server and everything seems to be working except the NoAutoRebootWithLoggedOnUsers entry. Without fail, over the last few weeks, our lab setup as well as our users have been prompted to restart their machines with a 15 minute time out and there's nothing they can do about it. They can't postpone or cancel the restart, all options in the prompt are greyed out. Below is the registry file we are using to connect our workstations to our WSUS server:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate]
"AcceptTrustedPublisherCerts"=dword:00000001
"ElevateNonAdmins"=dword:00000000
"WUServer"="http://xxx.xxx.xxx.xxx:8530"
"WUStatusServer"="http://xxx.xxx.xxx.xxx:8530"

[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU]
"AUOptions"=dword:00000004
"AutoInstallMinorUpdates"=dword:00000001
"DetectionFrequencyEnabled"=dword:00000001
"DetectionFrequency"=dword:00000002
"NoAutoUpdate"=dword:00000000
"NoAutoRebootWithLoggedOnUsers"=dword:00000001
"RebootRelaunchTimeout"=dword:00000030
"RebootRelaunchTimeoutEnabled"=dword:00000001
"RescheduleWaitTime"=dword:00000020
"RescheduleWaitTimeEnabled"=dword:00000001
"ScheduledInstallDay"=dword:00000000
"ScheduledInstallTime"=dword:00000003
"UseWUServer"=dword:00000001

There is a bit of redundancy, if you want to call it that, having both the NoAutoRebootWithLoggedOnUsers entry as well as the entries for RebootRelaunchTimeout but we wanted to see if we could either disable the restart, or give our users a larger window within which they could wrap up their work, etc. before restarting. Neither of these entries seems to work, but our priority is getting NoAutoRebootWithLoggedOnUsers working and any help with this would be greatly appreciated.