I just posted this link in the Windows 7 forum and reminded myself of what a great document it is so I’ll post this here. The issue was that someone didn’t know what Local, LocalLow and Roaming was and why they had to stick something in Roaming on Windows 7
The folder structure on Vista is the same.
This document has the best explanation I’ve found for what the three folder areas mean and how they are boundaries of data.
Windows Vista also has changed the Application Data folder structure. Previous user profiles did not logically sort data stored in the Application Data folder, making it difficult to distinguish data that belonged to the machine from data belonging to the user. Windows Vista addresses this issue by creating a single AppData folder under the user profile. The AppData folder contains three subfolders: Roaming, Local, and LocalLow.
Windows uses the Local and LocalLow folders for application data that does not roam with the user. Usually this data is either machine specific or too large to roam. The AppData\Local folder in Windows Vista is the same as the Documents and Settings\username\Local Settings\Application Data folder in Windows XP.
Windows uses the Roaming folder for application specific data, such as custom dictionaries, which are machine independent and should roam with the user profile. The AppData\Roaming folder in Windows Vista is the same as the Documents and Settings\username\Application Data folder in Windows XP.