The data will still be there. The question of whether there are any drivers required depends on the hardware you have installed on the machines. As Jope says, if they are base machines then you can just plug the hard drive in and it will work. If, however, you have added extra hardware to the other machine which requires software to be installed, then you will need to reinstall this on the other hard drive too. Also, be careful if you are moving a drive from a more powerful machine to a less powerful one, otherwise you might have trouble getting the software on the drive to run if the lower-powered machine is too slow or doesn't have enough memory.
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moto