I had a similar issue with the instal failing 3 times at 69%. The hard drive
I was using was in a cradle and I have previously used this as an external
drive.
Finally I tried the same self burned DVD in an other machine and the instal
sailed through first time. The compatibility test passed the first machine
but not with that particular hard drive in place so not sure if it was an
issue reading the DVD or if Vista is particularly fussy about hard drives.
I did notice Vista did refuse to format over an exsisting FAT partion though.