...like things that I would not expect a game to do.
For instance, when I launch from steam it throws up the 'running for the first time, installing...' dialogue before getting to the Stardock launcher.
When I launch from that the game takes an absolute age (well minutes, minutes longer than it should) to load, if it loads, sometimes it crashes & requires relaunching. 
When it is launching/loading successfully, it seems to do something odd to steam that looks to disconnected or stop it somehow. It also can disable the gamevox software I use briefly. I get a lot of the sounds windows makes when you connect a new device while it's launching, no idea what that is about?
When it has crashed it has produced odd side effects, like completely disabling the PC's audio, or making it so everytime I try to type in anything in chrome, it pastes the last thing on the clip board instead. Restarting chrome fixed that, & re-selecting the audio defaults fixed the previous issue, so they're not major things, just frustrating & annoying little weirdnesses.

Running i7-4770K, 16gb RAM, Win 10 Pro 64 (Ver 1703), AMD 7990 with latest drivers (not beta)

Any one have any idea as to what might be going on?