This tip shows you how to change your default IE download directory

Click on Start>Run and type in Regedit and then navigate to the key show below.

HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer

Change the value of the string "Download Directory" to the new path you want to assign as IE's Default Download directory i.e. "D:\downloads"

And that's all you need to do in order to change your default internet explorer download directory.