Arduino Malfunction

For some reason when I plug in my arduino, the following error appears:
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_recv(): programmer is not responding
Also the Tx and Rx leds just stay on instead of flashing when uploading code. In fact they turn on right when I plug my board to a power source
any help would be appreciated.

Did you choose the correct serial port? In arduino IDE, it's listed under tools-> serial port. Also try different USB ports and computers. There was one guy with two computers with disfunct USBs. Quite a mess but eventually figured out it was the computers he used.

Also the Tx and Rx leds just stay on instead of flashing when uploading code. In fact they turn on right when I plug my board to a power source

Does this happen when you are using an external battery pack instead of using USB cable to power the Arudino? It seems that something (could be either some programs on the PC or the code on your Arduino) is using the serial port and that maybe why you couldn't communicate with the board.

To see if something is coming out of the arduino board throught the virtual serial, just open arduino IDE and press the button on the right most location on the row, open serial monitor. It will receive stuff if arduino is sending. Crap if the baud rate is wrong or it's binary or it's purely crap to start with.