gui design - Button bar: criteria and position

Me and my team are (re)thinking some UI details of our main application.

It's a "traditional" desktop application for the Windows platform. It's a business targeted application, and our customers are accountants, professionals, lawyers and (overall) their employees.

Currently we have a button bar placed at the bottom of each window. The main problem about it, it's that sometimes there are too many buttons and there is no way to emphatize the most important actions from the less ones.

So we decided to split the button bar in two, getting the "action buttons" (buttons about actions who "do something with the items") apart from the "navigation buttons" (buttons which call actions that end closing the window), where:

• Action buttons are placed on the bottom left of the windows: New Item, Details, Print, Delete


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  Navigation buttons are placed at the very bottom right of the windows: Close, Back

  
  


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  Is it a good idea?

  
  


• It would be clear to the final users the criteria?

I have prepared 2 different images:

Updated - loaded on my Dropbox account:

Before:

After:

Thank you

Answer

In in Windows environment, I would see more the navigation bar at the top (unless it won't be very often used..in that case there may be a problem somewhere else). I'll place the action-button bar as a toolbar on the left or right. I slightly prefer the right because it's more natural for right-handed people.And that's what we have on most popular apps such as Office.

For highlighting some actions I think that using color schemes for differentiation is pretty effective.