Question Details:

I have a DELL inspiron 1520 notebook, recently during the work it gives me an error when I started, it shows a black screen the messages (invalid system disk replace the disk and then press any key) I change the boot order from BIOS but still it gives me error I change the HDD but it does not make any sense (the floppy and cd room are empty)

Answer:

First you should check the floppy drive, the CD/DVD drives, and USB flash drives, remove all and reboot.

Next, check the BIOS and make sure that your hard drive is detected. If it is, make sure that it is set as the first boot device in the boot order.

If you don't see your hard drive there, the connections to it have come loose or it is corrupt. You should open the case and check the connections.

If nothing works try to repair Windows using the Vista DVD of your operating system.