OK, so I've been having this problem since I got Windows10 two days after the release. Before that, I had W8.1 on a brand new Dell Desktop and everything worked and looked fine. The desktop and my video game filled the flat panel 1080p screen and the graphics were perfect. I installed W10, and everything looked low resolution (graphics were cartoonlike and text was scratchy and unresolved). I downloaded and installed the AMD drivers appropriate for my system and nothing changed. I tried installing and uninstalling it three times, and on the third time, after the upgraded driver, now W8.1 looked just as bad!!! I spent two hours online chatting with Dell Support and watching them go through all the Windows and AMD settings, uninstalling and reinstalling drivers, and nothing improved the appearance. At the end of yesterday, they decided to send me a new video card and a technician to install it ... and held out the likelihood that they'd probably have to do a restore to factory conditions --- eek!!!!
At 2:30AM, I woke up and decided to play with the system. I thought if it was a monitor problem, and that installing my old 1280x1024 Dell monitor might uncover it. As soon as I made the dual monitor connection, the screen resolution on the flat panel reverted to the smaller monitor's settings automatically and the image was perfect resolution! Of course, there's a black band on the flat panel monitor on either side of the desktop image, but I can live with that. I guess I also have to live with the smaller monitor tucked away under my desk to maintain the resolution. If I try to unplug the smaller monitor, the flat panel reverts to its larger image and poor resolution. I dare not attempt W10 --- haha!
If you've got some ideas as to why or how this happens and how I can improve upon this setup, I'd appreciate it.
Here's my specs:
AMD Radeon Graphics Processor (0x6811)
Internal DAC (400Mhz)
AMD Radeon R9 270
Samsung UN32EH5000 32-Inch 1080p 60Hz LED TV (2012 Model)
Generic PnP Monitor
Dell XPS 8700