Chaning Windows XP Permissions from the Command Line
Now that Windows XP is obsolete and everybody is using Windows 7, here's a tip that might have made your life easier if I had shared it sooner.
In Windows XP, you can run most programs as an administrative user by
right-clicking and choosing Run As. However, as far as I know you
cannot run Windows Explorer this way, which really gets aggravating
when diagnosing file permission problems. My workflow has been to log
in as the affected user, check whether the permissions work, find a
problem, then log in as an administrative user to change the
permissions, then log back in as the affected user again. Long-time
Windows users are used to this dance; their patience for their
preferred operating system is infinite. But I come from the Linux/UNIX
world, and I am used to opening a terminal window, running su - or
sudo, and performing administrative tasks without having to log out
and log back in.
As usual, Microsoft has come through for us. Sure, it's a pretty obscure trick, but it shows that our benevolent masters have only our best interests at heart. (Further evidence is that running commands as administrator is much easier in Windows 7.)
The first part of the trick is the runas command. Open a command
shell (Start -> Run -> cmd) and then type
runas /user:username cmd
If my domain is contoso and my administrator is admin, this would
be
runas /user:contoso\admin cmd
This will open up a new cmd window logged in as the administrative
user. (Come to think of it, maybe right-clicking the icon and choosing
Run As might work too. Oops.)
Now that you have a command-line window running as an administrative
user, you can launch programs as that user, which itself is useful in
troubleshooting problems. You can also change file permissions using
the cacls command. Typing cacls alone will give you a good summary
of the command (make your terminal window tall to see it all), but
here is an example. To change a folder Secrets so that user eve
has full access to it and its contents recursively, first navigate to the
parent folder and then type
cacls Secrets /E /T /G eve:f
You should one line be printed for the folder and all of its contents.