After not using the water for a couple of hours, when I turn it on from anywhere in the house, the pressure is fine for a couple of seconds, then it drops to a dribble, after one to four minutes the pressure comes back to normal, accompanied by a loud banging of pipes.
Has anyone encountered this problem? Would sure like to know what the cause is.
Thanks for any info.

Without knowing any details we can't address your complaint.
Pump or city water? If pump give details. If city water do you have a PRV, (pressure reducing valve) installed?
Give us something to work with here. Regards, Tom