We made a upgrade in our SP2010 environment and once this upgrade was completed,we noticed that the documents in the document library has an addtional feature "Add to my links" in the document properties drop down. i hope this feature was in SP2007 but not in SP2010. How to remove or disable this feature in our SP2010 system?
The "Add to my Links" is actually a SharePoint 2007 menu option, which actually has been replaced in SharePoint 2010 by a similar option available, by example in Library tab -> Connect to Office -> Add to SharePoint Sites (other locations too, explained here http://blogs.technet.com/b/praveenh/archive/2011/10/12/my-links-in-sharepoint-2010.aspx).
It should have been hiden by default - have you not Upgraded visually?? Still using the Old master page inherited from SharePoint 2007?
The reason you only see it now, it might be that you have configure User Profile syncronisation in SharePoint 2010. To make it disapear one way I see is to simply disable for those users (simpler for all of them, but i personally found it as a cool feature) via User Profile Service Application. The full procedure is explained here http://howtosharepoint.blogspot.ch/2010/11/hide-disable-my-site-my-profile-and.html, but in simple words it requires specifying which features connected to user profile are availalbe to which users/groups.
It is also possible that the configuration of the "Portal URL" property in the Site Settings could cause the appearance in ECB of the "Add to my Links"! Simply clear that property and it should dissapear.