Jacob Peatie is quite right (as always) - that said the following may help (your qn is unclear I've no idea what an"AD" plugin is and how it locks you out)
Check your wp_user table. Users have numeric IDs, passwords, email addresses etc. ID is incremented for each new user - on install first user (admin) will have an ID of "1". You cannot recover clear password but you can edit (back-up table first) the email to one of yours (maybe enabling you to be emailed reset options by AD plugin?), and/or change password using reset instructions mentioned by Jacob.
If ID "1" does not exist: (Often the first action on a new install is to create a new admin usually ID "2" or other low number, and then delete the original admin with ID "1".) Then one of the low number ID's is likely to be your "primary" admin for "AD" and can be similarly edited.
I don't know what the AD plugin does or your issues; there are probably simpler solutions such as just adding a new admin user and/or disabling the "AD plugin" by deactivating via WP dashboard, or by renaming the directory where plugin is installed.
Update following comment:
On Multisite you can identify super admins from "site_admins" in wp_sitemeta table - you will still need to refer back to wp_users table.
You could also try editing database to make your own WP user a super admin (I assume the plugin won't reset you to non admin). Edit wp_meta to change you to an admin (see step 4 here); and then edit wp_sitemeta table to similarly add your user to site_admins serialized data.
An alternative approach would be to identify the "primary super admin" username which should match an account and email address on your servers, if active contact the user, if not, reset the password to gain access to MS and WP as admin (I assume plugin access is not affected by resets).
However; I suspect the bigger issue will be maintain user access to WP when migrating from old to no, or new, plugin.
I doubt if I'll be able to suggest anything more I have little experience of MS Server and effectively none of AD.
