Are people here seriously recommending you install a copy of Microsoft office downloaded from something called "mega upload" ? Really? Or even "simply download a version off a torrent site" ?
I guess the security of your computer means nothing to you, you're willing to effectively give a random person on the internet administrator rights to your personal computer and all its files?
Crikey. If you need Microsoft software, buy it from the store. If you want to support OpenOffice, which I find to be excellent, then do so. But downloading pirated / cracked / who-knows-how-modified versions of commercial software and then installing it is just asking for trouble (imho).
I downloaded the PC student edition of Office from microsoft, without problem. What you do, is buy the Swiss student edition, then you can download the English version, use the key of the Swiss student edition, and away you go. Of course, it might be different for mac users.
Funny thing. The Swiss edition has proofing tools for French, German, Italian and English. While I'm a fan and user of OpenOffice, the proofing tools of MSOffice are far in advance.
OpenOffice.org does work and is legal, but if you need more functionality the real deal, with upgrades, new web functionality etc is probably what you need.
cheers