This seems to be a common problem with the dvd. Mine does it as well but at
different file %. Other folks and myself also have discovered that a "clean
build" rather than an update seems to work ok. I tried it on another pc and
the clean build option works. At the present time I don't want to clean build
my main machine as the version I am dual booting works pretty well until RC1
comes out next week.
For what it's worth, I was receiving the same error with the DVD ISO. Turns
out it was an issue with my CD/DVD-ROM drive. I switched my BIOS to boot
from my Plextor DVD burner, and I was able to install successfully.
I am having the same problem as the rest of you, but I have not found help in
any of the solutions you have had. Just booting off of the Vista DVD and
installing a clean installation will result in the "Error Code: 0x800703E6"
message. Specificly it gives me this after about 74% in the Expanding Files
tab. Just wondering if anyone has had any luck besides what was listed
above. My system isnt overclocked and it meets the system requirements. I
am trying to install Vista on a clean reformatted hard drive.