I've bought a Maxtor STM3500320AS 500 GB harddisk last month. I've shut down pc without any problem last night. But then when i opened the PC, it was giving this error message: DISK BOOT FAILURE, INSERT SYSTEM DISK AND PRESS ENTER I've checked the BIOS. But it didn't detect the harddisk. So i didn't get my files. I don't want lose all of my files. What can i do now?