Unlike it happened on Windows XP, on Windows Vista and Windows 7, the search results window doesn’t have (by default) a column with the folder path of the found items. Instead, it has a column named Folder in the form of Folder name (folder’s containing folder path).
I don’t know the reason behind this decision, I just know that it makes hard to sort the found files by its path.
Fortunately, the folder path of the found items can be added to the list view by right clicking on any list column and selecting the folder path to be shown.
Unfortunately, I couldn’t find a way to make it permanent. I need to do that for every search.