One of the reasons to switch over to the New Google Drive is that, with a little boost, it allows you to edit MS Office files (Word, Excel, & PowerPoint) without converting them into the native Google format first. This can be a real boon to folks who are getting documents from people that send them in Word and need to get them back in the word format. It can also somewhat mitigate conversion problems that arise from highly formatted Word documents when converted into the Google format--if you've tried this, you know it doesn't always go so well.
The video below is a step-by-step walk-through of how to setup your Google Drive to enable this compatibility solution. I say it in the video, but to be clear this is a Chrome-ONLY solution.