Help with arduino not connecting

I have a adruino uno. I having trouble connecting the board to my computer. I am using windows 7. when I go to the device manger it say that my board is connected to com 9 and the ide says com 4. So what am I doing wrong. I have downloaded the ide several times and reconnected the board several times. I have even changed to another board with the same results. I would appreciate any help you guys can give me. Thanks in advance
Lou

hey guys I just want let you know I have solved my problem. The way I did it was I changed boards again and went to the serial ports change the com port that was in the ide and made it the same as the device manger was. I also went thought and read all that you guys have posted. again I am very pleased with all the information you guys have provided. Thank you very much for all the help.
Lou