Well, this is such a dumb question that it doesn’t look like anybody’s asked it yet…
This happens a lot, sad to say. I’ll accidentally hit some combination of keys, and I end up in “proofreading mode” for lack of anything better to call it in Microsoft Word (Vista, if that makes any difference.) Everything I type comes out as red underlined words, paranthetical comments at the side of the document, etc. Then I absolutely cannot figure out how to get out of it in a document and back into regular mode. There has got to be an incredibly simple way to do this. The only way it ever happens is by accidentally hitting keys. How do I get out of this mode? And don’t be mean… I have brain damage, you know.
Just to clarify, the “Track Changes” mode is not the same thing as spell/grammar check. From the description in the OP, I’m pretty sure the issue here is the Track Changes mode, and you get out of it with Ctrl-Shift-E or by finding “Track Changes” in the menu somewhere (depends on the version of Word).
It really is a useful feature. I routinely get document drafts of proposals and papers to comment on or modify, and by using this feature the lead author can clearly see what changes I made. He/she can also choose which of the suggested changes to accept and which ones to throw out.
But Track Changes must be used cautiously - if used without due care when publishing, other readers can turn it on and see all sorts of information that probably isn’t intended. There’s been court cases on this, with much embarrassment for companies copying documents directly from other companies.
It’s a useful tool, yes, but remember to accept or reject all changes before publishing (or better, copy everything but the final paragraph marker in the final version into a brand new document). I think they’ve improved Word with additional tools to try to help keep this from happening.
Track Changes can also lead to document corruption. (It’s not common, but it can happen.) For these two reasons (privacy and corruption), I know a number of technical writers who won’t use Track Changes, or who only use it when absolutely required. (I’m one of them.)