This is what Dean Theophilou send me after I asked the same question: It prevents USERENV errors (error # 1000 in the App section of the Event Viewer). According to the author of the utility: "The service deals with userenv/1000 where the message indicates that the profile is not unloading and the error is "Access is denied". To accomplish this the service monitors for logged off users that still have hives loaded. When that happens the service determines which applications have handles opened to the hives and releases them. It logs the application name and what registry keys where left open. After this the system finishes unloading the profile." Apparently, a lot of people have this problem. I'm just glad that someone figured it all out. -----Original Message----- From: Seitz, Linden [mailto:L.Seitz@xxxxxxx] Sent: vrijdag 24 oktober 2003 13:45 To: 'thin@xxxxxxxxxxxxx' Subject: [THIN] Re: UPHClean What does UPHClean do anyway? -----Original Message----- From: Dennis van Turnhout [mailto:turnhout@xxxxxxxxxx] Sent: Friday, October 24, 2003 3:37 AM To: thin@xxxxxxxxxxxxx Subject: [THIN] UPHClean Since Robin Caron's hotmail mailbox is full I was wondering if someone has his e-mail address at microsoft or could mail me the tool? Tia, Dennis van Turnhout