To change from Control Alt Delete on XP to regular boot...
Goto Control Panel, then Administrative Tools, Then Local Security Policy
(Note you need Admin privilages)
On local security policies, click Local Policies, then Security Options.
Find: Interactive Login: Do Not require CTRL+ALT+DEL. Double click that, and select Enabled.
Reboot PC.
For normal multiuse, go back to Control panel, then User Accounts. On the mainscreen, select "Change the way users log on or off"
Then select "USe the welcome screen" and then you can enable fast switching too
Now to bypass admin password - I believe their is a method with a Windows XP CD and the recovery console...
This works too
http://www.lostpassword.com/windows-xp-2000-nt.htm