I've swapped HDs between PCs and my old Powerbook and newer Macbook several times without issue. You will have to get the OS-X disc somewhere. Probably buy it. There are no (legal) downloads of it available. On May 20, 2009, at 3:50 PM, Arne Hulstein wrote: > Can I put a harddisk that used to live in a pc laptop in my tibook > to replace its dead harddisk? And how do I get MacOS 10.4 back on it > as it came installed with it and I have no cd's around here... Are > there tibook downloads? > > Arne > _______________________________________________ > Titanium mailing list > Titanium at listserver.themacintoshguy.com > http://listserver.themacintoshguy.com/mailman/listinfo/titanium