I am starting with a fresh install of XP SP2. PC is on a domain. I can login user after user just fine. Then I install Siebel Web Client 8.0 and any user I login as slow boots, about 5-6 minutes and then doesn't process the netlogon script. I log the user off and log back in, netlogon scripts process just fine and this process takes a normal amount of time. So there must be something in the boot process killing this. I noticed in the ntbtlog file that all the drivers stop loading after MUP.sys but I know that may be coincidence. Also, Add/Remove programs uninstall of Siebel brings the PC back to normal boot times and netlogon script gets processed. I've been working this issue for about two weeks now.