Definitely **do not go to HR** and create a problem where there isn't one.

Free life advise:  I would urge you to train yourself to be respectful in the workplace and *focus on looking a woman in the eye*.  

For some, eye contact is uncomfortable and in that case focus on the area between her eyes ( this worked for me as an awkward young man ).

As a side note, if a woman is uncomfortable with the occasional glances, a minor adjustment to a professional conservative work attire usually can fix this ( in short hide most of the cleavage and don't expose upper thigh ).  

If a woman chooses to expose major amounts of cleavage or thigh, a certain number of guys are going to glance no matter what.