Hi Glamgran,
You can disable "Run As" command by following the steps given below:
Disable the RunAs Service on a on a Windows XP Computer:
The service that is required to run the Run As command is, by default,
started automatically when you install Windows. However, the service can be
disabled by an administrator. This you can do by following the steps given
below:
1.Log on to the computer as Administrator, or log on as a user with
administrative permissions.
2.Right-click the My Computer icon, and then click Manage.
3.In Computer Management, expand the Services and Applications node, and
then click Services.
4. In the details pane, right-click the "Secondary Logon" service, and then
click Properties.
5.In the Properties dialog box, set Startup type to "Disabled", and then
click Apply.
Click OK to close the Properties dialog box, and then close Computer
Management.
The service that is required for running the Run As command is now disabled
on your computer.
For more information you can access the KB article given below:
http://support.microsoft.com/default.aspx?scid=kb;en-us;294676&Product=winxp
S.Vijay
This posting is provided "AS IS" with no warranties, and confers no rights