A file recovery util often work pretty well. At least it will show file name and a message that file content is rewritten by another file. If it doesn't show special file types at all (like *.cs for C# project (yes, *.aspx.cs file's extension is .cs)) most likely this only means these files aren't deleted. Why? Because something saved it fot you.
E.g., on Windows System restore is enabled by default and will track all *.exe, *.ini, *.ico, *.cs, etc. files. You can use something like System Restore Explorer to browse restore points (not working on Windows XP) or browse it by hands: <drive letter>:\System Volume Information\_restore<GUID>\RP<integer>\<new short name>.<original ext> (and original modification date).