Use this tutorial :
Default File Associations - Restore in Windows 8 http://www.eightforums.com/tutorials/8486-default-file-associations-restore-windows-8-a.html 1.Scroll down to the table and select .....
.exe
2.Save the
.reg file to your desktop.
3.Double click or right click
.reg file > select
Merge 4.If prompted, click/tap on
Run,
Yes (UAC),
Yes, and
OK to approve the merge.
5.Restart computer to complete the process.