Ok so I downloaded the driver from LG for my optimus G (Sprint), and when I plug it in I keep getting that message. I have been able to root it, but I can't transfer files to and from it. (This message happened before and after rooting, and I have restarted). Now i will try to organize all the information in a list because if I try explaining it with words and sentences it becomes incoherent and I ramble, hence the more cavemanesque speak shal prevent that.

Windows 7
Front USB port (first tried in hub, then directly)
ZV9 Optimus G Sprint
Had Optimus S (Got LG software for that, Might be old)
Have restarted PC since driver install.
Message is: Software Driver Installation - LGE Android Net MTP Device X Failed
USB cable came with phone
Selected Media mode


Sadly that is all I can think of. So if anyone has any suggestions it would be much appreciated.