Cygwin permissions on Windows 7

Question

I suppose this question is related to a previous answer on Cygwin permissions, but I have failed to work out how the answer can be applied to my situation.

I am finding that when I edit a file (~/.screenrc in this case), I can make one change and then the permissions and ownership are reset. This is what I am doing after I make a single change to reset permissions again:

Chi Site - ~/wd
Sun Jul 30 - 03:12 PM > ls -la ~/.screenrc ; chown -R RobertMarkBram:Users ~/.screenrc ; chmod 777 ~/.screenrc ; ls -la ~/.screenrc
----rwxrwx+ 1 Administrators None 1921 Jul 30 15:12 /home/RobertMarkBram/.screenrc
-rwxrwxrwx+ 1 RobertMarkBram Users 1921 Jul 30 15:12 /home/RobertMarkBram/.screenrc

I read in the previous answer on Cygwin permissions about changing the set up of paths in /etc/fstab. This is what I have there, but it has not made a difference:

none /cygdrive cygdrive binary,posix=0,user 0 0
none / cygdrive binary,posix=0,user 0 0

These are my mount points:

Chi Site - ~/wd
Sun Jul 30 - 03:20 PM > mount
C:/cygwin/bin on /usr/bin type ntfs (binary,auto)
C:/cygwin/lib on /usr/lib type ntfs (binary,auto)
C:/cygwin on / type ntfs (binary,auto)
C: on /c type ntfs (binary,posix=0,user,noumount,auto)
D: on /d type ntfs (binary,posix=0,user,noumount,auto)

Answer 1

This is a case of PEBKAC.. I had done too much messing around with permissions and didn't know how to get back.

Firstly, under Windows Explorer > that folder > properties > security I noticed there was a NULL SID there that I removed.. my own user didn't have all rights anymore but the the EVERYONE group did. Then I followed advice on this social.technet.microsoft.com post: Permissions all messed up on folders within my profile on Windows 8

cd /d c:\[folders or files you would like to reset permission]
icacls * /T /Q /C /RESET

It took awhile but restored permissions.