Windows 8 Pro won't install from dvd Error Dx8007045a

Running Windows 7 Home Premium and trying to install Windows 8 Pro from purchased DVD.
Opted to install updates online as suggested by Setup the chose upgrade keeping files and applications (not a clean install).
No matter what I do it fails every time after PC check with:

Windows encountered an unexpected error.
Verify that the installation sources are accessible and restart the installation.

Followed by:
Setup is unable to launch Install.exe
A dynamic link library (DLL) initialization routine failed.
[Error Dx8007045a].

I've spent an afternoon going around in circles - please help!

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Stewie56 said:

Opted to install updates online as suggested by Setup the chose upgrade keeping files and applications (not a clean install).

Click to expand...

1) Try with no updates.

2) Try a clean install:
http://www.eightforums.com/tutorials/13375-clean-install-windows-8-upgrade.html

Probable causes: 1. Your install DVD is damaged and cannot be read.
2. Your optical drive is faulty and cannot read the DVD properly.

Solutions: Install from a pendrive.Try to create a bootable pendrive with WINToBootic from another computer - that way problem #2 is taken care of. WINTOBootic will straight away take your DVD - no need to create an ISO.

WiNToBootic - the ultimate Windows 7/8 USB Boot Disk Maker

In any case avoid a clean install if you want to keep files and applications.