I use Moodle in a corporate environment, but we are just in the beginning phases. You may be able to convince your IT department to allow you to have a separate virtual server on their Microsoft servers (that would seem ironic to me, since most people would virualize a Linux server, not a Microsoft one in order to run an OSS database and web server with applications). If you can not, perhaps it is because they are only comfortable with Microsoft applications.
There are ways to run OSS applications on Microsoft, though it is probably easiest to install Moodle on a L.A.M.P. system (Linux, Apache, MySQL, PHP) stack. The problem is the administrative overhead: if your Network Administrators don't know or feel comfortable with using MySQL and PHP, then the task you are asking them to do is overwhelming to them. You are giving them a series of new applications that they need to become familiar with and competent with. It is unfair to ask them this without approval from their Supervisor, since it will use up their time to administer Moodle, as well as their time for training to learn Moodle, PHP and MySQL.
Perhaps you will be best suited to use a commercial LMS application. The other choice is to use a hosted Moodle solution. Using some other Moodle host means your Network Admins don't have to be involved except for integrating with LDAP for authentication.