"Microsoft Program_name has not been installed for the current u

I get this error message when I open any Microsoft Office 2003 program. I've
tried http://support.microsoft.com/default.aspx/kb/898512 and it isn't that.
The main problem is that other users on this computer can use the Microsoft
Office programs and my account can't. All the accounts are administrators
and I do not have the option to reformat etc. I tried creating another
account and trying but instead the new account is spammed with installers but
still goes through without an error message.

I have been able to use this program for the past 4 maybe 5 years without a
problem. All of sudden out of the blue I get this message.