How to export the system registry

[Ryan Sanders]

I am writing a batch program for all versions of windows
to recover lost CD_ROM drives after
installing/uninstalling roxio. First I need to backup the
registry. All is fine in the other versions of windows
untill I come to XP. I used the command "regedit /e
c:\bacup.reg" My beta testor said that the file was not
created. Can someone tell me the command reguired to do
this?
Thanks,
Ryan Sanders