New expired patent

A few days before the ephemeris of the expiration of the RSA patent an obsolete new one arribes from Microsoft. Remember in September 20th 2000 expires a patent from the 1983 (about an algorithm invented in 1977) how license exclusivelly the rsa company to explode the use of:

c = m^e (mod n)

Patent it's suposed to mean a technological advance that the company developer needs to has an exclusive to explodes in term of refund the inversion. But if you (and me) think what can be a discover when the algorithm date from 6 years before, we will not understand about the new microsoft patent...

How can be, now a day, patented the ``Page Up'' and ``Page Down''? Read in many places about this question (spanish, english). For how long this keys are in the keyboards doing the task recently patented?