Why does my mouse pointer disappear on Sims 3?

This is a new keyboard and mouse.  I had the computer built by CyberPower and had them install Windows 7.  However, I think I may have found the problem..  Anytime I ran the Sims 3, I had windows open in the background.  I usually kept The Sims Exchange open or an Explorer window open and that was when my mouse cursor would be invisible.  Yesterday I had rebooted the computer and when I started The Sims 3 my mouse cursor was visible, but when I minimized my game and searched for something, the cursor disappeared .... The explorer window being open was the only difference.  So, I closed the window and the cursor reappeared.  I rebooted the computer again and left explorer open but minimized, launched the game; and again the cursor was invisible.  Once the window was closed the cursor reappeared.   The issue seems to be when a window or program is open or running in the background, the mouse cursor becomes invisible.  It doesn't seem to matter if the window is minimized or not.  So maybe this is the same for the others that have this problem, even with the Mac.  I hope this helps others.  🙂