In the conditions listed by the poster, there is no mention of changing the motherboard or upgrading the BIOS, so it is enough to read a piece of data from the BIOS.
Unless the BIOS is upgraded, it will not change, only some Only computer enthusiasts who have no interest in life will upgrade the BIOS. They will die if they don't do this. However, the data of the same motherboard and the same BISO version is the same. If the financial software is encrypted, the machines in the entire unit may be common. As for the graphics card , the BIOS of the same graphics card is the same, there are too many cases, and there is no encryption meaning. The hard disk hardware serial number and the network card serial number are unique in the world, so it should be considered.