I reinstalled everything and went through all the steps.
   everything works fine now. Dont know but i think i might have forgot
to choose the uno board in the tools menu.
   Thank you for your suggestions and help, I appreciate it.

shut down all programs and verified arduino is com 3.
  but no change

Usb powers up arduino uno but cannot upload.
"com port 3 already in use" is displayed when i try to upload.
     Im having this problem on my new laptop, everything works fine on my desktop.
            Desktop running XP
            Laptop running WIN 7
Any help would be great, thanks.