My machine is on a concrete floor and when the spin cycle comes on it vibrates all over the place,how do i fix this?

Hi from France,

All washing machines need to be 'level' and not able to rock. Spin cycles tend to show unballanced/level machines 'best'!
Is it possible that the concrete has been worn in some place(s) under the feet? If so:-

There are (normaly) 4 feet and at least the 2 front ones are adjustable- sometimes all 4 but the rear ones are difficult to get at!
You need to ensure that the front feet are adjusted/screwed down tight to the floor. In my experience washing machines are delivered with a flat spanner to facilitate otherwise an adjustable will be required. If one foot is easy to turn THAT is the one which needs screwing down until it becomes fairly difficult to turn further. Check by rocking the machine fairly hard- without moving its position on the floor.

Hope this cures,

Cheers,
John C