In MS Word, how do I reset the word checker....?

Tools > Options, "Spelling & Grammar" tab. Select the custom dictionary, click "Modify" and remove the mistakes.

somebody has replied to you in the thank you to alter the default language yet having mentioned that, all human beings makes use of their computers for countless issues, some produce technical artwork, scientific, engineering etc so what you do is that in case you type in some thing which comes up as a mistake like color (whilst us of a is color) whilst the purple line seems you do not forget approximately approximately, yet stunning click and upload to dictionary. exceedingly with unusual names and addresses etc you upload to the dictionary this is like instructing a youthful newborn, you're including to its vocabulary.

Simply search for and open the Custom.dic file then delete the incorrect words

Find and rename the file "custom.dic". That is the dictionary listing that you created. Word will recreate a blank one.