Upgrade fails with Installation Sources error

I'm looking to do an in place upgrade of Win7 Ultimate to Win8 Pro. I am running a Lenovo Thinkstation with SAS Raid, 2 quad core processors and 24 gig of memory. The raid is configured raid 10 and is one 500gb partition (C Drive). I have a secondary 2 TB sata drive that I used for swap and backups (D Drive). Video card is a NVIDIA Quadro FX 1700.

I downloaded the release image from my MSDN account, along with a key. I expanded the ISO to my D: drive, disabled my AV and ran setup. I go through the regular checks and it asks for my key, I type that in, agree to the license and click next. After about 3 minutes, I get the following error:

The timing seems to be just as it's ready to start copying source files...



I also burned the ISO to a DVD and tried that and got the same result. I've checked my partition and disks for errors (checked raid manager and ran chkdsk/f) and no luck.

Any ideas? My goal is an in-place upgrade.

Thanks!

I had a very similar message to that on a computer when upgrading. I never did isolate the exact culprit, but I overcome the problem by going into Task Manager and ending all the non critical processes that I could find, then running the installer again.

Also. How are you mounting your ISO? You will need to make sure that it is set to auto-mount so when you restart it is available again to continue the installation.

Did you try booting to the DVD just to test?

But your are in Windows 7 to start the install. You select the Setup on the DVD and you get that error?

Because we seem to have 2 folks with source problems, I wonder if the supplied download is bad. I can't test it myself. Have you checked the hashes?