Yesterday I was working with my new SharePoint 2010 development farm. I had an InfoPath form template (i.e. .xsn file) to deploy. I opened up SharePoint Central Administration and went to the General Application Settings page (i.e. generalapplicationsettings.aspx on the Central Admininstration site). I noticed that the "InfoPath Forms Services" section between "External Service Connections" and "Site Directory" is missing.
Obviously I didn't have the Enterprise version installed. So here's how I solved it:
1. Go to MSDN subscriptions - http://msdn.microsoft.com/en-us/subscriptions/downloads/default.aspx
2. Login and open/expand the Servers link in the left navigation to find the "SharePoint Server 2010" product.
3. In the content panel you'll see the "SharePoint Server 2010 (x64) - DVD (English)" product information display. Click on the "View" link of the "Keys" column. Copy the "Enterprise CAL" product key for use in step #7 below.
4. I opened up SharePoint Central Administration and went to the (i.e. upgradeandmigration.aspx on the Central Admininstration site).
5. In the "Upgrade and Patch Management" section click on the "Convert farm license type" link to bring up the Conversion.aspx page.
6. Enter in the new product key and convert to the "SharePoint Server with Enterprise Client Access License" edition.
7. Now go back to the General Application Settings page in SharePoint Central Administration and you should now see the "InfoPath Forms Services" section with its links.