Well Heres my take.
The Formatting shouldnt have made any Difference to your Overclock.
However what you describe could either be the following.
1. Windows Install Was corrupted at those Overclock settings.
2. Motherboard drivers problems...Perhaps reinstall and get the latest ones.
3. You have Bad memory modules. Test your memory.
Now When you install an OS you should return to stock speeds to avoid issues mate. I would try this before and RMA.
The Formatting shouldnt have made any Difference to your Overclock.
However what you describe could either be the following.
1. Windows Install Was corrupted at those Overclock settings.
2. Motherboard drivers problems...Perhaps reinstall and get the latest ones.
3. You have Bad memory modules. Test your memory.
Now When you install an OS you should return to stock speeds to avoid issues mate. I would try this before and RMA.