And let's not get licensing confused with product activation.

Any MS product that requires activation will only do it 3 times before you have to call MS. After 3 hits into MS's database for that key, you need to do it over the phone. If you have crashed a PC and only changed out the hard drive, for example, a reactivation will not count as a hit to the total. It's an MS algorithm based on the MAC address of the NIC, and other hardware diagnostics, it sends in conjunction with the CD key to activate your product.

So, to quote the subject line: NO... it cannot be installed on 3 computers. It can be activated -- serially -- on up to 3 computer configs, then you have to call.

A license for Office can be on a home PC and a laptop for travel, but they cannot legally be used concurrently.


Update: applies to all versions of Office except the S/T version.