I wanted to download music/transfer pictures to/from my Charge and my laptop is not recognizing it. The phone shows it is receiving a charge from the laptop when connected and it is not the usb cord either. I used the USB cord that came with phone. I used the same cord with my Kindle and it recognized that.
You need to install the Samsung driver for the Charge phone on your PC. The latest one is 8,341 K Bytes. It is V1.3.1900.0
There is an earlier version that is 23,347 K Bytes and it also says V1.3.1900.0
In my I-510 Charge phone the latest one (8,347 K Bytes) seems to work better but I was using the earlier one until recently.
If you cannot find it I can email it to you if your email will accept a large 8,341 KB file. Also, if I do email it to you I will change the .exe to .txt so when you get it all you will need to do is change it back to .exe.
I had the same problem for the longest time. It turns out I was using my wife's LG Dare's usb cable. All worked well as soon as I went back to the cable that came with the phone. While trying to fix the problem I installed a newer driver for the Charge on my laptop, now when I connect I get two sets of prompts asking how I want to connect.