Hello, I've been reading many of the posts about upgrading 32bit XP to 64bit
Vista.

People seem to agree that the retail upgrade disk will be bootable for
troubleshooting purposes.

However, there still seems to be controversy as to whether a person can
install 64bit Vista as a bootable disc. So far, the discussion tends to
favour that it won't be possible.

Can anyone provide a once for all answer, from experience with an actual
Retail Upgrade Disc or definite knowledge from Microsoft? This would also
help others with this same question, without need to read through all the
posts.

Thanks.