Access Denied

Hi
Have a machine that had Windows 98, I have upraded the machine to Windows 2000 professional , with no server. But it has some access restrictions. I want to take all restrictions off the machine. I have logged onto the machine as the administrator, and cannot access all the functions, like, ICW, Change the registry, Look at Shared folders. I have used GPEDIT.MSC, Poledit for windows 2000 and XP, Have Reimaged the pc with the Original image, looked at the items using poledit, and none arerescricted. Upgraded again and still the same problem, Updtaed the critical files, Made sure the Modem and Network card drivers are up to date. … How would one reset all restrictions to default> ?