.htaccess file

[Connie]

Bob,

this is a question which I would ask your hoster's support
as I do not know how the subdomain is configured

maybe an empty .htaccess is created when you define a subdomain in your administration panel?
That's what I guess

but to be sure: why not save the .htaccess of your root before you install and compare after installation?
THat will be the safest way and it does cost only 4 minutes ;=)

Cheers, Connie