How to "git add ." when some files are not accessible (permission denied)?

Hello --

First of all: I'm using Git with Windows. Most of the time it works 
*very* good, but now I've a problem that might appear to Unix users as 
well. I had the idea to use Git to track changes in my C:\WINDOWS 
directory. I thought the following would work:

$ cd /c/WINDOWS             (1)
$ git init                  (2)
$ git add .                 (3)
$ git commit -m "Initial"   (4)

And then issue "git status" or so to see the differences after 
installing or running some software.

However, when issueing (3) "git add ." it adds hundreds and thousands of
files and then stops with

     error: open("foo"): Permission denied: foo
     fatal: unable to index file foo

The file "foo" is not accessible for me, even though I'm administrator.
This might occur to Windows and Linux persons as well, I guess. The 
adding stops overall.

The question is: is there a way to tell "git add ." to add all files but
ignore those that cannot be added due to lack of authorization?

Or, more generally spoken: can I tell "git add" to add only those files 
it can handle and ignore the rest? The "-f" switch doesn't work and some
exclude lists on a per file basis are not applicable for my purpose as I
don't know the files in advance.

I'm aware that I could do it with some fancy shell commands, but very 
often I was surprised how many really cool commands Git offers to "do 
what I mean". Wished other software would be so usable :-).


Cheers,
  -- Dirk