Just a legal point - you can't register alphanumerics as a trade name, only trade NAMES. I'm not sure how far you can push it with letters, as by that definition "Expee" would be registerable, but XP not. I know with numbers it's just not considered a part of the name - So Windows is copyrighted, but 95, 98 etc are not. I hate with a passion the politics of Microsoft. I wouldn't mind them taking over the world as long as they had a decent product with a positive attitude to customer support, instead of their belief that it's just something else they can charge the poor sucker consumer more cash for. However, in this case, I do sympathise. We are talking about companies competing in the same market. If Lindows was a game, or a piece of hardware, then I am sure Microsoft wouldn't have bothered. But it's a bit like a Japanese motor manufacturer bringing out a car called "Phord". The problem lies with whichever plonker chose to use the "Lindows" name in the first place. The intention is obvious, particularly since "Lindows" is not a real word - the image is "Like Windows, only for Linux", and that is obviously trading on Microsofts image as market leader. Me, I'd have called it "Doors". Doors are an entry, and are of robust construction. Windows break all the time.