@ Thurak: The DXDiag you sent me didn't show any hint which might have caused ur issue unfortunately.
@ Thurak/Tanooshman: Could u do the following:
1. Download DepencyWalker (64-bit version):
http://www.dependencywalker.com/depends22_x64.zip
2. Unpack the files into a folder.
3. Drag-and-Drop the XRebirth.exe file from the SteamApps/coommon/X Rebirth directory onto the depends.exe file.
The dependency Walker should now show up showing a list of DLLs and other things.
4. In the DependencyWalker click on File -> SaveAs.
5. Make sure that Save as type is set to Dependency Walker Image (*.dwi) and save the file somewhere.
6. Send me the file by PM (maybe better pack it, since it might be some MB in size).