My cursor runs off the screen and will not return. How do I fix this problem?

Occasionally I will lose control of my cursor as it "slides" off my screen. Sometimes I can press Ctl and Esc and it will return. Other times I have to restart the computer before the cursor will reappear. I am not a computer nerd so give me specific instructions as to how I can fix this problem. Thank You in advance for your istance!!!!!!!!!!!!!!!!!