much software , including the windows, is all about stealing it , not about using it, so they do allow a person to run "One Instance" of. the problem comes in when there are 100 instances running on 100 different computers that only 1 was paid for.
Dual booting does not run more than one instance of.
If you suspected that your not following the licence agreement and are costing MS money by your method, then you should ask them. or spend 2 hours interpreting the leagese of the EULA