I cant upload programs to my arduino

Using Arduino IDE 1.x
1

Hi!
i recently got an arduino uno R3
im using win 7

i have read a lot of forums and blogs but i cant seem to find the solution to my problem.

i get either one of these to messages :

1//// avrdude: stk500_getsync(): not in sync: resp=0x00
avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51

or

2//// com ## is already in use

while the arduino is conected the L led flashes 3 times and stops for one second.

please help me
same problem on my other laptop

2

Does the Arduino serial port appear under Tools->Serial Port? If not, check that you have the drivers installed.

Did you select the right port under Tools->Serial Port?

Did you select "Arduino Uno" under Tools->Board?