I have a Dell Inspiron 530 0X0000007E error code

You can replace the Main board but how is the cost compaired to a newer machine? You can repl the main board with out much if any hassel to your windows install. If you repl w/ a different manufacture main board you will have to re-reg with windows.

That error message is usually coupled with removing an adapter connected to a RAID device. Have you disconnected anything in your computer recently? Have you opened it and cleaned it recently? If you've opened it to clean it, there's a chance that something may have come loose. If you know what you're doing on the inside of a computer, you can go through and make sure that everything is properly connected and then try booting again too see if that works.