MS Office

[#1]

Some time ago I purchased MS Office which I installed on my desktop and laptop.

If I change my desktop and/or my laptop can I transfer MS Office to a new machine?

[#2]

I see no reason why not, you own the license not the machine, and I don't think it would do MS any favours by not allowing it.

[#3]

Yes you can transfer Office to a new machine, I have done this multiple times without any problems.  

[#4]

The licence for my version of Office (2007) allows it to be installed on 3 machines. Over the years it has been installed on various combinations of machines without issue.