Moving an extract

I'm working on exercise 6 (Masks and Channels) in Classroom in a Book. I extracted an image (Foxtail) and I'm unable to move it to another file. I can move the extract within it's window but I can't move it to another image/file (the Egret file). I'm using Photoshop 7.0 on Windows XP.

Are you trying to drag it to another OPEN image? If you have Auto Select Layer checked in the options bar you may not get what you expect. Uncheck, target the layer in the layers palette, then try the move.