Moe, have you tried updating through a different method, known as Firmware Over-The-Air or FOTA? Basically, it will let you update your LG Optimus L7 via a wireless connection, so you wouldn't need to use your USB cable with the PC anymore.

According to the instructions on LG's Support site, you can do the FOTA update quite easily. First, go to Menu and select the icon that says Software Update. It will take you to the Settings page. In Settings, scroll down and look for Phone info, then select Software update. Select Check now for update and it should give you options on how to proceed. If it shows you that there is an update available, just follow the on-screen prompts and instructions until your phone gets updated.

Hope that helps! If you still need more info see the LG Support page here.