Uploading Troubles in Aruino Uno Rev 3 in windows

my device manager in windows 7 detects me the arduino device in com22 and wen i try to upload it says the the com22 is already in use.the previous program that i have uploaded was hello arduino !! Serial.println . I am not able to overwrite it . HELP ME GUYS
The following are wat i have tried :

  1. Reset the board during the IDE display compiling
  2. reinstalled the driver , restarted the windows
  3. unplugged the board while uploading and reconnected back soon.
    HElP ME on this guys