A very common error when running windows easy transfer , especially on a laptop. Even when there is plenty of disk space free you keep getting the above message.
The reason for this is, when you start an easy transfer it not only copy's your users files and setting but will also take a copy of any recovery partitions you may have. For example on a lenovo or dell laptop there will be a separate partition for factory restores
Open up your windows easy transfer file
Click on Customize then Advanced
In the following window you will see the selected partitions , in this example C: D:, untick the partition that contains the recovery partition that you do not wish to copy. If you do want to copy it you can map it to another drive.