I can't get into Linux.

[Shelagh Manton]

I'm back on Windows (bother!) again. I've done something and I can't log 
into the Gnome desktop.
The log in procedure goes well until I get to the log in page. Then I get a 
message saying that it can't open 
/usr/share/gdm/themes/Bluecurve/Bluecurve.xml.
I opened one of the other terminals (ctrl-alt-f1) and looked for the file. 
It is still there. But cd /usr/share/gdm/themes/Bluecurve complains that 
Bluecurve is not a directory. Using vi on it tells me that Bluecurve is a 
directory and that it includes Bluecurve.xml. I did open Bluecurve.xml with 
vi and while I could not tell if anything was wrong with it, it had text in 
it which seemed OK. Eg not scrambled text. I looked at the file permissions 
and nothing obviously stupid there eg root owns it and drwxr-x--x (this is 
approximate as I forgot to write it down). Where should I go from here?

Shelagh