Spent all day Saturday trying to fix a win 7 laptop that was running very slow, this included updating windows 7. Updates installed without problem.
Even after clearing out all the crap it still ran slow (Intell M900 2G ram).
Yesterday I updated it to Win 10 64 bit, electing to keep nothing, the machine now runs very well considering its poor chip and low memory.
Remember the free upgrade to win 10 is only on offer for the next couple of months.