try this
AccessDenied
http://www.nt.unets.ru/john/
Access Denied is a simple, but effective security program for Windows ® 95/98/ME. It allows you to lock out unauthorized use of your computer. While away from your computer, you can rest easy knowing Access Denied is reliably protecting your computer and data. Also Access Denied can save your laptop or desktop PC from thiefs
you can get WinGuard Pro 2003 FREE version.
http://www.winguardpro.com/