I have an 15" HP Spectre X360 laptop with a 4K display. Whenever I run a VMWare guest OS. it always upscales to 4k which on a laptop, makes the text much too small to read. I have gone through a number of different approaches that many people say fixes the issue, but haven't had any luck until today. Here's how I fixed it...
In VMWare Workstation, click "Edit | Preferences" then select the "Display" preferences.
Under "Autofit", de-select "Autofit window" and "Autofit guest".
Under "Full Screen", make sure "Stretch Guest (no resolution change)" is selected.
After that, start up your guest OS, and set the resolution using the display settings built into the guest OS. Then when you go full-screen, the guest OS will fill the screen as best it can, without the host passing on a resolution change message to it.
That was it for me.
Note: Using the "View" menu on VMWare to resize, autosize, or fit the guest may make it all crazy again. When that happens, I find that if I manually specify the resolution in the guest again, then shut the guest down and restart it, making sure I ONLY stretch it to full screen, I can overcome it again.
There really needs to be a setting in VMWare that allows me to ONLY increase the resolution of a guest OS UP TO a specified max. It should assume the full display is that max, and then scale the guest appropriately inside of those boundaries. Why this is so hard for VMWare engineers must be because they aren't using the latest laptops with 4K displays. I just upgraded to VMWare Workstation 14 Pro this morning in an attempt to fix this issue and it is still persistent.