syntax highlight problem in gvim 7.3

Question

I upgraded my ubuntu to 11.04 and my gvim got all messed up. I am basically starting from scratch and need some help. Upon recommendation, I am starting to move everything related to vim (plugins and vimrc) into /usr/share/vim/vimfiles

after
autoload
colors
doc
ftpplugin
gvimrc (file)
nerdtree
plugin
snippets
syntax
vimrc (file)
vimrc.dpkg-old (file)
vimrc.tiny (file)

I also have a .vimrc file in /home/laptop/.vimrc This file actually contains the settings/mappings that I've added

:set runtimepath fetches:

runtimepath=~/.vim, /usr/share/vim/vimfiles/vimfiles, 
/usr/share/vim/vimfiles, /usr/share/vim/vimfiles/vimfiles/after,
~/.vim/after

I have no folder like the one mentioned above /usr/share/vim/vimfiles/vimfiles

Questions: Why are there two vimrc's? should I swap contents of /usr/share/vim/vimfiles/vimrc with /home/laptop/.vimrc?

Errors

Error detected while processing /home/laptop/.vimrc
line 6
E484: Can't open file /usr/share/vim/syntax/syntax.vim

Line 6 is:

syntax on

my /usr/share/vim/vimfiles/syntax originally only contained snippet.vim, however, the /usr/share/vim/vim73/syntax folder contained many many other files. like gdb.vim, jsp.vim, groovy.vim, libao.vim...etc (more than 60 files)

so I copied all of those files to /usr/share/vim/vimfiles/syntax but still error is there

how can I get back my syntax highlighting?

Update

• had vim73_backup and now changed it back to /user/share/vim/vim73
• :set rtp? does not have vim73 (as shown above)
• :echo $VIM $VIMRUNTIME shows /usr/share/vim/vimfiles /usr/share/vim/vimfiles since this is wrong..how do I get vim73 here?

Answer 1

• There is no reason to copy the files in /usr/share/vim/vim73 anywhere else. Your gvim already knows about those files and sources them when needed. You should remove from /usr/share/vim/vimfiles any files you copied there unchanged from /usr/share/vim/vim73.
• Vim looks for runtime files (e.g., syntax files) in several places. These places are specified in the 'runtimepath' ('rtp' for short) option. You can read more about this in
  
  :help rtp
  
  You can see the current value of 'rtp' by executing
  
  :set rtp?
  
  As you can see from that, Vim already looks in ~/.vim, /usr/share/vim/vimfiles and a few other places as well as /usr/share/vim/vim73.
• You need to find out why you are getting that error message at line 6 because the :syntax on command should not be looking for syntax/syntax.vim in /usr/share/vim/. That suggests that your $VIM and/or $VIMRUNTIME variables are messed up. Try executing
  
  :echo $VIM $VIMRUNTIME
  
  The result should be /usr/share/vim /usr/share/vim/vim73.
• In addition to what benizi wrote (as I was writing this), you can find out about the various vimrcs on your system by reading
  
  :help vimrc
  
  You can also see where your vim is looking for its vimrcs by executing
  
  :version
  
  and you can see what files your vim has actually sourced by executing
  
  :scriptnames

All of that is probably not enough to completely fix your installation, but it will be a good start towards finding out what's broken and understanding where various files should go. We can go from there to get it all working properly.

Answer 2

You appear to be misinterpreting the suggestion in the question you linked.

Don't put anything in the globally shared /usr/share/vim/(anything) directories. As you discovered too late, it may well be overwritten when you update Vim.

Instead, put custom files in directories under a directory called .vim in your home directory. So, if you had a custom /usr/share/vim/vim72/syntax/gdb.vim file, put that in $HOME/.vim/syntax/gdb.vim. If you have a custom colorscheme, put it in $HOME/.vim/colors/name-of-scheme.vim.

To directly answer the question you asked, though, here are the purposes of the various vimrcs you've mentioned:

/home/laptop/:
    .vimrc            - your personal .vimrc (won't be touched on upgrade, etc.)
/usr/share/vim/vimfiles/:
     vimrc            - systemwide `vimrc` (affects all users on the system)
     vimrc.dpkg-old   - possibly your pre-upgrade modified version
     vimrc.tiny       - systemwide `vimrc` for the 'tiny' version of Vim