Solved Deleted windows 7, now windows 8 doesn't boot

[jumanji]

Basically, what happened is you had Win7 installed as primary OS. That is where the boot partition and files were located.
when you deleted the 7 partition you deleted all the boot info as well.

My recommendation as others have suggested, back up your data wipe the drive and Reinstall 8 as the primary OS.

Sent from my WP7

Exactly. The root cause has to be tackled at its root. And here it is reinstall Windows 8 as the primary.

And reinstalling Windows 8 and getting it activated is not difficult anyways.