I have this mobile disk it's a usb 2.0 and it's a 4gb. I have instructions for installing the disk but I don't understand them. And I need help on how to get it goes so I can start saving things on it. Can anyone help??

You should just insert into your USB port and your system will recogniz it, you may need to upsate your USB driver to the 2.0 standard, it is possible you still have 1.1 drivers for USB
Make sure you go to thte Microsoft update site and get all avail updates if you haven't already
http://www.update.microsoft.com/microsoftupdate/v6/

If this doesn't help, what don't you understand in the instructions