A repetitive clicking noise coming from a laptop is usually a sign of a failing hard disk drive (HDD), which is a type of storage device that uses spinning platters and moving heads to read and write data. A failing HDD can also cause severe delays in input and output operations, as well as data loss or corruption. The technician should replace the HDD with a new one or upgrade it to a solid state drive (SSD), which is another type of storage device that uses flash memory and has no moving parts.