Windows 10 HELP! Windows could not complete installation 9879

[chilisausage]

Hi guys. I've installed the windows tech preview since release on my mbair mid 2012. I have fun messing with beta software though not much knowledgable with the technical stuff. While installing the latest build 9879. This happened during the final steps of the installation (pic attached). Can anyone help me with how to fix this. Thanks!

Btw I'm using the OS X partition right now. If there is any way that I can save the installed OS on windows without erasing or refreshing the installed apps, it would really be appreciated

 

[Jimbo22]

What is the make/model of PC/laptop? What is the primary OS installed on it? Is this a clean install? Did you partition the HDD and isntall windows 10 TP on the newly created partition?