Ok so today I saw an ad for an Intel Mac core 2 tower for sale. When I contacted the owner he invited me over to see it. I saw that the case was not typical apple casing (more like a super fancy gaming case) but the operating system was obviously Mac OS X 10.5.7. I clicked and opened programs and everything seemed fine. However, when I got the computer home and I connected it to my monitor and keyboard, it started booting like a Windows PC. As the process went on, it showed the apple icon and the progress bar then the grey screen. finally, when it got to the part where the "log on" screen or the desktop should pop up.. there was nothing but a blue screen. What happened?? I am so confused. It's like all of the sudden it's a windows computer! I tried booting it up from my Mac OS X 10.5 disk but it wont read from any mac cd/dvd. It does, however, recognize windows cds and DVDs and will boot from those. Does anyone have any information on this... or can give me any (serious) advice?