File Names with (2) suffix

I have many folders and files with a (2) suffix as in \Program
Files\Microsoft Office(2) and \Program Files\Common Files\Microsoft
Shared(2). Please help me to understand what these are. There are also the
"same" folders without the suffix. I assume that the folders and files with
the (2) suffix are duplicates.

About two years ago, I did a system restore and that's when I first noticed
them. In reviewing them a few days ago, I noted that none of them have been
modified or, as far as I know, even accessed.

If these are, in fact, copies of folders and files before the system
restore, and given that I don't want to go back to them, can I delete them
and what is the risk?

I appreciate any help in understanding these system files.