Thats the problem cant contact airtel device i fine signal is fine only hdd is faulty now that i have changed it i think i need the right formatIt has a unique boot loader signature. Probably formatted with FAT32 or ExFAT depending on the size of the hard disk or partition. The file system is decided by the manufacturer of the STB.
Better get Airtel to advise you. Though I am doubtful they can help and will suggest a replacement.