uploading error

I have an Arduino Uno and a program of mine which worked 2 years ago. I've resurrected it but when I attempt to download, usiing the verbose option here's what I get. I'm on a Mac.

Binary sketch size: 5978 bytes (of a 32256 byte maximum)
/Users/billmeng/Desktop/Programs/Arduino.app/Contents/Resources/Java/hardware/tools/avr/bin/avrdude -C/Users/billmeng/Desktop/Programs/Arduino.app/Contents/Resources/Java/hardware/tools/avr/etc/avrdude.conf -v -v -v -v -patmega328p -cstk500v1 -P/dev/tty.usbmodem0000121D1 -b115200 -D -Uflash:w:/tmp/build9193058972150331273.tmp/Snow_prototype.cpp.hex:i

avrdude: Version 5.4-arduino, compiled on Oct 9 2007 at 11:20:31
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/

System wide configuration file is "/Users/billmeng/Desktop/Programs/Arduino.app/Contents/Resources/Java/hardware/tools/avr/etc/avrdude.conf"
User configuration file is "/Users/billmeng/.avrduderc"
User configuration file does not exist or is not a regular file, skipping

Using Port : /dev/tty.usbmodem0000121D1
Using Programmer : stk500v1
Overriding Baud Rate : 115200
avrdude: Send: 0 [30] [20]
avrdude: Send: 0 [30] [20]
avrdude: Send: 0 [30] [20]
avrdude: ser_recv(): programmer is not responding
avrdude: stk500_recv(): programmer is not responding
avrdude: Send: Q [51] [20]
avrdude: ser_recv(): programmer is not responding
avrdude: stk500_recv(): programmer is not responding

The systemwide config file is missing, which may be the problem. If so how can I reconfigure it other than deleting all of the Arduino programs and re-installing all.

What model Arduino?

Are you sure you have the right Board and Port selected?

Does the Receive light on the Arduino blink when the upload starts? If not, the messages are not getting as far as the Arduino.

The board is a Uno, the board and the port is correct and the lights blink when uploading.

I have been unable to find the configuration files,

System wide configuration file is "/Applications/Arduino.app/Contents/Resources/Java/hardware/tools/avr/etc/avrdude.conf"
User configuration file is "/Users/billmeng/.avrduderc"
User configuration file does not exist or is not a regular file, skipping

Cpat:
User configuration file is "/Users/billmeng/.avrduderc"
User configuration file does not exist or is not a regular file, skipping

Ignore this error.

If the Receive light blinks and the Transmit light doesn't then your bootloader is not responding. Did you ever swap out the processor? Did you ever upload a sketch via ICSP? Did you ever burn an alternative bootloader via ICSP?

Sounds like it is time to burn a fresh bootloader. Do you have an ISP device or a working UNO to use as an ISP?

Did you ever swap out the processor? Did you ever upload a sketch via ICSP? Did you ever burn an alternative bootloader via ICSP?

No to all of them. I was planning on getting another one anyway, so I guess that's my best option.
Thanks!

Cpat:
No to all of them. I was planning on getting another one anyway, so I guess that's my best option.
Thanks!

Your best option is probably a USBasp for under $4 on eBay. It's much easier to use a real ISP than ArduinoISP.