You will have to give us more details if you want us to help you and not speculate on what it can be... also, it would be a good idea to fill out the "My System Specs" to help even more.
My Computer
At a glance
Windows 7 x64 (Ultimate)Intel i5-4670K8GBs Ripjaws 2133MhzAsus GTX660 (2GBs)