I don't use Windows, so can't guess what it may have done to your here, but it's generally best to set your screen resolution to the physical monitor resolution. If you set it to other than native resolution you can get some horrible looking displays. If native resolution is too small for you to comfortably read, don't fix that by changing resolution, fix that by using settings in the OS and in applications themselves. I'm sure Windows must support this, but it's been eons since I used that, and couldn't begin to tell you where to find the settings.

Since you've had problems before (albeit fixed by a reboot), you might want to consider not doing writing on top of your computers keyboard. Maybe set up a small table to the side of your desk for writing on. You can get folding TV trays that would work for this (not the cheap metal kind we had as kids, but nicer wooden ones).