How old/big is your hard drive? May be you need to update it, because this could be a reason why can i change look of mail in windows 10 pop-ups. By the way, good using habit and regular maintenance will extend its life span.Third -- Unreasonable startup or shutdown operation.
Sometimes when you hurry to do something else, like go shopping, hung out with friends, you may force a shutdown to close the computer as it is much faster than normal operation, but in fact it is rather bad behavior, voiltent and may cause windows errors like can i change look of mail in windows 10.Fourth - Baddly programmed third party applications.
Baddly programmed application is likely to be a reason of can i change look of mail in windows 10 error, when users install or uninstall programes, especially uninstall some applications, some vital or important data/files may be deleted accidently. Next time, when you launch the computer or open a program, that file can't be found, then error will popups.