Unfortunately, yes. OEM license is tied to the computer, it is first installed on. Legally, it cannot be transferred, it lives and dies with its first computer.
Thats the reason OEM copies are cheaper than Retail ones. And remember, MS is obliged to provide tech support only on Retail copies, not on OEM ones.
However, you can make small hardware changes without requiring reactivation. E.g. if you only replace memory or only replace a hard drive. For MS, motherboard is the computer. Changing it will definitely deactivate you, unless maybe you are able to replace it with the same, identical model.