i dont think its any of that and lol, exactly wtf is a defrag gonna do for this problem? also mouse options, cmon. sounds like her mouse is clicking fine, there isnt cursor, click speeds or anything like that wrong, which means windows is doing something(aka opening search windows) and id put money on if u go to the start menu/control panel/ folder options/file types and scroll down to folder, click advanced and make either explore or open as the default it should fix ur problem, if its not listed try clicking new and making one called open or explore and making that default, click apply, ok etc and see if that works.
o and not enough ram makes search windows now. i dont think some of her ram grew legs and ran away so how come it hasnt always done it if it were ram? itd take more memory to open a search window and get the search engine loaded then the contents of a folder as long as it was a small to moderately sized folder