Can't be temperature issues?
What miner you are using? Try to lower intensity.
Is the Windforce new? Old, long time used GPUs may fail unexpectedly.

P.S. You should be asking in altcoin section ( to move the topic use link at bottom left )

EDIT: I see your MB has only 1 PCI-e x16. Are you using powered risers?
What if you put the windforce in PCIe x16 (alone) is it working?