The Iris Pro 5200 is on the edge of working with current Resolve. It's a wobbler, maybe yes, maybe no. Don't have that exact GPU to test with, so can't be sure.
As a test, try Resolve 16.2.8 which should for sure work with that GPU. If 16.2.8 works and 18.x doesn't, that would indicate the GPU is not supported in current Resolve.
Of course the whole Bootcamp thing throws in an additional wrinkle. Not something we test so don't know if that might be part of the problem.
You can find 16.2.8 in the Support area for DaVinci Resolve / Fusion on the BMD website:
https://www.blackmagicdesign.com/suppor ... and-fusionIf that doesn't work, then put 18.6.2 back in, and provide the following info:
In a File Explorer window, go to:
C:\Program Files\Blackmagic Design\DaVinci Resolve
and run CaptureLogs
This will place a Resolve log file named similar to this on your Windows Desktop: DaVinci-Resolve-logs-20181228_140434.zip (You may not see the .zip extension if your system is set to hide known extensions).
Then open the Windows System Information app and do a File - Save (Not a File Export), which will generate a .NFO file.
Place both those files on a file sharing site and provide links to the files here. Make sure the links don't require access credentials.
If you are a new Forum user, you may not be allowed to post URLs. If this happens, just put a space near the front of the URL, so the system doesn't think it's a URL.