ah, acrobat. since adobe Rights Managment Documents use the extension .rmf they take over the Rich Map File. just right click it, choose "open with" and select your version of hammer. make sure the checkbox saying "always use the selected program to open this kind of file" is ticked, then click ok. you might not have the old hammer icon back, but if you double click it you will see the hammer logo appear (the window asking what game you want to edit it in will apear behind the logo, so you have to click the little bit at the top or bottom to bring it up, then just choose your game)