Your gutters were likely originally installed using spikes and ferrules. The system works, but eventually the spikes come loose, causing the gutter to droop or fall. Pounding the spikes back in creates a temporary fix, but, as before, the spike eventually comes loose again.
New gutter systems use fascia hanger brackets. Slip the front of the hanger on the front lip of the gutter and secure the other side to the fascia of your home. This will secure the gutter to your home without you having to replace the entire system.
Leave the old spikes in place to keep the water and other moisture out of the holes in your roof. If your shingles hang over the roof, purchase the hanger brackets where the screw is already installed. They allow the head of the screw to stick out more, making for easier installation.
Properly working gutters are a must for keeping your basement dry and your foundation free from cracks.