Hacktronics 20x4 LCD Ripping my hair out ;repost with complete information.

First thing I'd do is get uploading working.
Make sure you can upload the blink sketch and that it blinks
using an Arduino board that is connected to nothing but the USB connection.
Then go modify the blink sketch to change the blink time to blink faster or slower
and do the upload again.
Once that is working, go back to trying to get the LCD stuff working.

I wish I had thought of that.

Don