I growl at technology

I am taking a break from re-plotting to go through the top-line text edits of my first draft, and for reasons of version control, am doing these edits in Scrivener, rather than in my over-sized and rather lumpy Word document of the whole 100,000 words. But, for some INFURIATING reason, EVERY new word I type comes up with a red line underneath it. And sometimes the word next to it too! I KNOW HOW TO SPELL 'THERE'. AND 'MIND'. AND 'TO'. But currently, my computer doesn't believe me.