Hi all

Had the same problem installing AVAST 2014 under Windows 8 (x64) on a new Toshiba Satellite i3 notebook.
Jumped through the usual hoops (ran Malwarebytes, deleted Page and Hibernate files, but as Windows 8 does not have a ‘safe mode’ needed another solution.

  1. Ran ASWCLEAR to remove ‘failed’ installation of AVAST 2014
  2. Rebooted
  3. Installed PREVIOUS version of AVAST (124 Mb) successfully!
  4. Updated to 2014 via MAINTENANCE function.
    All OK!

I suspect the actual cause is one of the plethora of proggies and services that gets loaded with these propriety products.

Hope this works for you.
KenE