I want to upgrade the IOS on an 837. I backed up most of the Flash Directory, however there are to files

8 3689 pre-l8on

9 3775 post-l8on

That it won't copy. I've not come accross these before? Do i need them? An ideas what they are?

I expect i'm missing their file extension which is why the won't copy, how can i find this out?

Kind regards

J mckechnie