pert:
By default the Arduino IDE creates a folder used for the sketchbook at C:\Users{user name}\Documents\Arduino (or whatever the equivalent is on your system). It seems that for some reason your user does not have permissions to create that folder or else that location is not accessible.It is possible to change the sketchbook location but that is easiest to accomplish via the Arduino IDE (File > Preferences > Sketchbook Location). Since you can't currently start the Arduino IDE, it might be easiest to try a workaround by putting the Arduino IDE in portable mode. To do this you only need to create a folder named portable inside the Arduino IDE installation folder. That will cause the sketchbook to initially be located inside the portable folder, though you can change it to any location you like later via Preferences.
Actually that's exactly what I was doing when I reinstalled! I followed directions above to get rid of that user data folder sketchbook area and then rebooted, reinstalled and prior to launching put in the portable folder i saw somewhere online. It worked, I closed it and went about my day. Came back to launch and boom it happened again. By the way it did create that folder,
Why God? WHY???