Some have the standard X clips holding on the key - take the clip off the bottom of the key and place it on the keyboard, then press the key into place.

If it is not an X clip but a spring clip shaped like "|___|" , leave it attached to the key, and put the ends of the clip into the corresponding holes on the keyboard, then snap the key the rest of the way into place.

Cynthia...thank you more than you know...so simple when you know the trick. Have a great day.

I am having the same problem, specific to the spacebar key on the dell inspiron ]7000. Do you know of a picture or a graphic that shows how the two plastic peices shaped as you described ([____]) are assembed? I spent two hours last night trying to get the space bar to pop back on, but it just wouldn't attach itself to both plastic peices.

Brad