I had to uninstall AVAST 8 in order to install VMWare Workstation 8. With AVAST in my PC the VMWare WS8 installer could not finish the installation. It failed with an error 1920. Error 1920 indicates an inability of a service to start. In this case it was a newly installed VMWare service. Now I am afraid of re-installing AVAST with VMWare WS8 installed.
The problem seems to be vmware and not avast!
See this thread
Funny that I installed VMWare 8 on my windows 8 system yeasterday with no problem
Why would the problem be with vmware when it works just fine with every other anti-virus out there? Avast seems to interfere during the installation, and this also affects workstation 9 and player 5 as well.
Here’s another thread reporting this problem: http://forum.avast.com/index.php?topic=126795.0
Have you even read the link I gave you ?
Did you try the suggested things there ?