You're going to have a lot more success running Odoo on a Linux machine. There's no reason you would want it to run on IIS (not that it would).

I am running Odoo in an Ubuntu virtual machine in my laptop. The VM has 8 GB and two processors. The same VM runs Odoo server *and* the Chrome browser to access the server. I just clicked around from module to module, opened some items, edited, saved, etc. Performance is every bit as good as any ERP system I have ever used.

Points:

1. If you will stay on Windows, be sure your machine is optimized for the application (I don't really know what that means in Windows).

2. Convert to Linux for the server. It isn't that difficult. This guide walks you through: http://openies.com/install-openerp-odoo-9-on-ubuntu-server-14-04-lts/

Server Fault can help with your other questions.