System keeps rebooting into Windows partition
I set up a Windows partition and installed Win 7 using Boot Camp. Everthing was fine for a while, until Win 7 did an update. Since then, my Mac Pro insists on booting into Windows upon power on. Also, the Windows installation appears to corrupt itself spontaneously. Is there a "hidden partition" that's at fault here? Can this problem be fixed without having to reinstall Windows? Thanks!
Mac Pro, Mac OS X (10.6.8)