Error Windows\system32\cmd.exe

I have been getting a small C: prompt window when my desktop is loading ( the top of the window says  C: Windows\System32\cmd.exe) it stays for a while untill all my icons and such are loaded then disappears after my entire desktop is loaded.   Can anybody tell me what is causing this I can't seem to get rid of it.  I have done several thorough virus scans and adaware scans and nothing comes up.  I tried to restore to when i didn't have the problem but it came back and now that i have defragged  i have lost my previous restore points for Norton Go back   Can anyone help me.....please  my last resort will be to restore my entire system with my restore disks ( and we all know how long that takes)  Plus I don't want to re-install everything if I don't have to