Taskbar icon issue

This is gonna sound like a dumb question, but how do I set my taskbar applications to not a create a second icon deck when I open an application? So what I mean by this is for example, when I have no instances of Chrome open, there is a single Chrome icon in the task bar (the application icon itself). When I open an instance, instead of just layering the new icon on top of the original one it opens a second one beside it, an them layers all additional chrome instantiations on the new icon deck. So whenever I'm using Chrome, I have the original application icon, and then a deck of icons representing all other open Chrome windows. I'm using Chrome as an example, but it could be any application. It's weird though cause it seems to only happen with some apps, but I can't find it in any settings anywhere. Anyway, any help you could offer would be appreciated. Thanks.

 

Shoot. Sorry. Yeah It's Windows 8 64 bit. No SP.

 

So I solved the problem like so:

1. Open chrome from taskbar, you will now have two chrome icons in the taskbar
2. Right click the 'new' chrome icon, and select 'Pin to taskbar'
3. Right click the original icon and select 'Unpin form taskbar'

Not sure why it was doing it, but the above steps solved the issue anyway.