So I got this PC from work, and it was used on a daily basis by customers (Anywhere from somebody that doesn't know what a mouse is to graphic designers) I bring it home, go buy a copy of OSX and try to install that to remove the stupid work software. Upon rebooting it at home, I get the grey screen either blank, with a folder and finder face on it, or a folder with finder face, that changes to a question mark. What does this mean and how can I fix it? Any information would be greatly appreciated. Oh, also I've tried: New ram, New HDD, PRAM reset, cmos clear, pretty much everything. And I can't figure out how to remove the CD-ROM itself. (Not the disk, the whole enchilada) Thanks!