if i have more then 1 internet explorer windows open, all of them closes at once if i close 1. why is this?

Answer 1

IE7 does not do this. You can have multiple instances open and when you close one that is all that closes.

If you have more than one TAB open when you close Explorer you will get a dialog box asking if you want to close all the tabs. There are options to turn off this dialog so when you close Explorer all tabs will close.