The requested resource is in use - Part II

As I mentioned before, when I try to open any Administrative Tool (Event
Viewer, Services, etc.), try to run a .exe file, try to run cmd, try to run
msconfig, etc, I get a "The requested resource is in use" on any
administrative group user account (I have no standard user accounts).
However, if I login as Administrator, everything works.

I tried these boot configurations in msconfig (I login in as Administrator,
make the changes in msconfig, restart, then login as the user) with these
results:
Safe boot - Minimal (this works!)
Diagnostic startup (the problem is there)
Selective Startup - All system services, no startup items (the problem is
there)
Selective Startup - No system services, all startup items (the problem is
there)

So what could be causing this? i doon't know how to further eliminate the
cause.

Thanks,
Mark