Running XP on VirtualBox 6.1/Win10 Pro. Laptop screen resolution is 1920x1080 Scaling set at 150 % (recommended) for Win10 Related VM settings With current value, apps, and fonts in guest OS blurs. But if ScaleFactor is set as 1, the guest OS appears too small. How to fix it?
For XP the only way is to use 200% scaling. That way it would do 1 pixel to 4 pixels perfect matching. Clear type looks wrong then so you have to disable that too. Overall it would look like a very low resolution LCD screen, but still sharp.