How can you open an old file?
This is going to depend on the type of file that you are trying
to open. The file extension is created depending on the software
(and version) that was used. For example, if you use an older
version of Microsoft Word to save a document, it has a .doc
extension. If you use a newer version such as 2007, it will save
the files with a .docx extension. You would need to have the
correct software to open the file, but in many cases, Microsoft may
make a viewer that you can download (depending on the file of
course)