Linux vs. Microsoft, theft?

Revised question, actually.
The class debate is that Micro claims that Linux stole their patches or something along those lines. I’ve been put in to the Linux group, and therefore have to defend it with my little-to-no-knowledge of the whole situation. I’m doing soem research, but I’d really appreciate any opinons you guys have, defenses, attacks from either side. Advantages and disadvantages?

My position is to start up the argument and give a general overview of the situation at hand and layout the arguments for the next speaker. Aye.

Can I do with Linux what I can with XP?

I’ve had so much trouble with Windows (prolly my fault for not having good anti-virus software and downloading too many torrents etc) that I’m thinking of converting. But I have no idea what I can do with Linux, if ABC application works on Windows will it also work on Linux? How about MS Office and other MS software? Also, why do so many people choose to have both on their PCs? (have I just answered my own Qn?). Advantages and disadvantages? Cheers.

From an anti-virus POV I guess Linux is much safer because most hackers will focus on windows.

See, I’m getting this notebook a week from now and I’m choosing between the one with Windows and the other one Linux. Do they have differences? What are the advantages and disadvantages of choosing one of the two?