I read http://wiki.mikrotik.com/wiki/Manual:License but not found answer. Can I move hdd with RouterOS (x86) to another hardware ? If the performance is not enough now or mainboard is damaged, for example.
License is related to hdd only. If it crashes you are lost unless you convince the mikrotik support to issue another license to you for free. There is no right for it but they may do a favour to you. So you cannot expect that. These are the conditions you knew before buying a license...