after you resize the window for windows explorer, before closing it, click Tools/Folder Options. Then scroll down the list and make sure there is a check mark in "remember each folders view", click Apply, and click the button that says "like all folders" on the View tab.
Click OK at the next window, then close it.
Try reopening a folder and see if it holds the size now...then try rebooting the computer and open a folder to see if it still holds that size.
Remember it. When I reboot or sometimes when I must turn the power off due to a system hang up all my folder windows revert to their original default size instead of the size that I have previously set them to? This is aggravating since I normally operate with at least three windows open and sometimes more. What if anything am I doing wrong. Naturally I am talking about Windows-XP SP-2.