Hi, I fully understand the inconvenience you have encountered. I suggest you first disable all the restrictions in SteadyState and check if those restrictions are related to the issue:
1) Disable the restrictions in "Global Computer Settings", "Set Computer Restrictions".
2) Turn off "Protect the Hard Disk".
3) Unlock all users in "User Settings".
4) Cancel all the restrictions in each user.
5) Restart the computer if you would like to apply the previous settings.
If disabling the restrictions in SteadyState does not cure the issue, I recommend you contact with our system newsgroup and check if this is system related:
http://www.microsoft.com/communities/newsgroups/en-us/default.aspx?dg=microsoft.public.windows.vista.general
http://www.microsoft.com/communities/newsgroups/en-us/default.aspx?dg=microsoft.public.windowsxp.general
