I'm currently using Win 7 on my partitioned drive since I can't get OS X to boot. Here's what I did to screw everything up: Installed SL awhile back without performing what people here are referring to as a "clean install" (I had lots of third party apps installed). Things seemed to be working fine, though Finder seemed to lag more in 10.6 than it did in 10.5. Today, however, I tried updating Parallels 4.0. It required that I reboot in order to finish the installation. But, when the Apple logo appeared, that damned spinner just wouldn't stop. [Perhaps Parallels is "tainting" the kernel?] I've tried a number of things to fix the problem. First, I tried reinstalling from the SL Install DVD. No luck there. I tried downgrading to 10.5 (archive and install). Still didn't boot. I even tried several volume repairs. Those didn't help either. So, now I've heard that some users are having luck booting in safe mode. But, if I try that, will I be able to transfer data to a backup drive? Any suggestions?