Hi All Due to some historical ineptitude, I have ended up with this situation. On my Server, I have UserA, with User ID 1001, and Group ID 1001. On my main laptop, I have User A  UID 1001  GID 1002 User B  UID 1002  GID 1001 I've just discovered this.  Now, when I open files on a NFS share, they're shown on my laptop as owned by User A, Group User B, despite the server thinking they're both User A. On my laptop, I need to change the group IDs round in the /etc/group file so they're consistent with the user IDs.  I also need to change any files legitimately owned by User A or User B to have the "correct" group ID. User A is my main laptop user.  I have got another - User C I can login as. I suspect, what I'll have to do is Login as User C #something like... #change files gid 1001 to gid 4444 sudo find {magic to find Gid 1001} {exec's strange syntax to} chmod :4444 "the file" #change files gid 1002 to gid 1001 sudo find {magic to find Gid 1002} {exec's strange syntax to} chmod :1001 "the file" #change files gid 4444 to gid 1002 sudo find {magic to find Gid 4444} {exec's strange syntax to} chmod :1002 "the file" Then I'll need to change the GID numbers somehow in the Group file. The simplest way I can think of is just edit the file, save it, then immediately reboot. Before I do this, can anyone see any GOTCHA!s? Any suggestions or advice please? Thanks in advance. Steve