Eclipse and Windows 7 have a bit of a feud. There is no option to pin Eclipse to the start bar. If you create a shortcut you can pin the shortcut, but when the app is run it creates a second item.
Found a post that fixes this annoying issue.
Be aware that you’ll need to edit the file as Admin if you installed Eclipse into a system location. Best way is to go Start > “WordPad” > Right Click > Run as Administrator, and then open the file from inside the application.
Twisted Pair Development 