Hi, 

I am using Windows 8 Enterprise, while installing windows 8.1 preview; the set up was almost 50% completed and then suddenly a message appeared which said "Windows 8.1 preview installation has filed".

I have no idea why is this happening?

Mudassar

Windows 8.1 Enterprise 8.1 Preview requires a 'clean install" on an empty drive or partition.  Please describe how you are going about installing it.

Hi, 

Since the installation process will conflict by 3^rd part service or program, I suggest we enter the Clean boot Mode in Windows 8 and try to install the preview version again.

How to perform a clean boot to troubleshoot a problem in Windows 8, Windows 7, or Windows Vista

http://support.microsoft.com/kb/929135  

If the issue persists, please help to collect setuperr.log and setupact.log under c:\Windows\Logs\PBR\PreRollbackLogs and post it here for further research.

Please upload them to a file sharing service like Skydrive or "Rapidshare" and put a link to them in your reply.

Link for how to  upload below.

http://www.wikihow.com/Use-SkyDrive 

Look forward to your response.