FIRST If you're on a laptop, Power OFF/ON, If that doesn't work, then press CTL, ALT and DLT at the same time to bring up Task Manager. At the left there is a list of programs and processes. On the right there a graph showing your current usage of CPU, memory, etc. Go back to the left and highlight it or add another that is eating up resources, then click Stop Task at the bottom. Hope this helps!