To use it as a data drive in your new desktop, you can just fit it into one of the drive bays, join it with a suitable power cable to the power supply and use an appropriate connector cable between mobo and drive, for accessing the data, if it is an actual drive with a case. If it is a PCI card drive, then you will need a motherboard that has the correct card slots to receive this SSD.
If you want to use it as the OS system drive too, then you need to clear the license key with MSoft as suggested, or buy a new license and transfer the 'ownership' to the new mobo installation. New device drivers will be required for the new kit, as suggested above.
If you just want to access it and keep it external, then get hold of an appropriate drive dock that has the right connector for your drive and plug it into the new PC as an external drive