Cannot set a Win7 Folder from read-only

When I installed Windows 7, it made my data folders read-only (for files in those folders). I go to properties, uncheck "read-only", tell it to apply to folder and subfolders, and it cranks away for a minute or two. Then it shows read-only uncecked, I click ok, and when I check the properties again, it's still read-only. I cannot update my data files! Unchecking and clicking ok has the same lack of effect. What to do?