startx problems, permissions?

[Chuck Theobald <chuckt at darkwing dot uoregon dot edu>]

Hi,

I have complete installs of recent versions of cygwin and cygwin/x (setup 
version 2.457.2.2, 6.8.2.0-1 of the xorg-x11 packages) on Windows XP SP2 
and have a problem with starting the X server.  If I log in as a user with 
admin privileges, or the user who installed the software, I can start a 
bash shell and run startx without problem.  However, if I log in as another 
(Windows domain) user, often I cannot even start the bash shell (permission 
denied by Windows).  By changing security settings on c:\cygwin, I can 
generally start the bash shell, but I cannot start X, getting the error 
dialog containing:

A fatal error has occurred and Cygwin/X will now exit.
Please open /tmp/XWin.log for more information.

Vendor: the Cygwin/X Project
Release: 6.8.1.0-5
Contact:
XWin was started with the following command-line

X :0 -multiwindow -clipboard


The contents of /tmp/XWin.log contain a message saying that /tmp/XWin.log 
could not be written to.  Changing permissions of this file (as an 
Administrator) to 666 avoids this, but subsequent attempts still produce 
the fatal error with a message to the effect that a socket could not be 
created.

Is there a definitive document describing the necessary permissions on a 
Windows box to permit use of Cygwin and Cygwin/X by users authenticated to 
a Windows domain?  If not, can someone offer advice on how to get this 
running so my office can make use of cygwin/x as something other than a toy?

Thanks,

Chuck Theobald
System Administrator
The Robert and Beverly Lewis Center for Neuroimaging
University of Oregon
P: 541-346-0343
F: 541-346-0345