Issue: Convert a basic volume to a primary partition

Hello,

I am currently using Windows 8.1 and I wanted to create a T partition, but when I created it, all other volumes except for one became "simple volumes" and are no longer "primary partitions," including the one that Windows 8 normally boots from, if I'm not mistaken (namely drive D, unless I'm wrong).

However, it seems to me that you can only run an operating system from a primary partition.

Here is a screenshot of the current situation of my hard drives:
http://www.noelshack.com/2015-49-1449268381-probleme-partition-base-2.jpg

Do you think I can shut down my computer without fearing problems when restarting normally with Windows 8.1? If not, what should I do to fix the problem and/or change the simple volumes back to primary partitions?

Thank you in advance for your help!