I want to dual-boot the Windows 8 preview, but before I do that I want to make sure I can uninstall it. If I use EasyBCD in Vista to rewrite the bootloader to the MBR, will I be able to safely delete the Windows 8 partition?
If you turn the active bit off for Vista before you install W7, it will put its bootloader with W8 (and not auto dual boot it with Vista. You can then boot W8 by default and add a Vista entry. The BCD in Vista will remain separate and unchanged.
But as CG says, it's not important. Vista/7/8 all use the same MBR/bootmgr/BCD. It's just the release number gets higher. Older can have problems booting newer because of digital sigs, but you should have no problem with the newer version remaining behind.
You never need to rewrite the MBR unless a different bootmanager (XP, Linux, 9x) has altered it.
Thanks for the info but is the last bit really true? I have installed W8 but I haven't seen my old "W7" boot menu again, only the new W8 blue boot menu. Am I missing something here? Do I have to push a button to view the old "W7" boot menu?