l did an Event Trace using xbootmgr.exe from Windows SDK and found LogonUI.exe causing huge delay along with wininnit.exe before the system can actually shutdown completely. l remember modifying DisableLogonBackgroundImage string in regedit along with modifying "C:\Windows\SystemResources\Windows.UI.Logon\Windows.UI.Logon.pri" the file that contains the logon background image and also "C:\Windows\System32\Windows.UI.Logon.dll" but l made backups, and restored everything to default, even used sfc /scannow or /scanfile on those specific files but had absolutely no success with fixing the problem. What else could cause the huge delays?(You can also hear the HDD doing weird I/O's when trying to kill that damn LogonUI proccess; sometimes l would assume that my HDD head is scratching the platters because of it)