There is a more recent claim of performance issue after upgrading to win 10:
http://forum.cyberlink.com/forum/posts/list/49330.page . This user got no help from win 10 users.
PepsiMan himself said in the past that he had issues after upgrading to win 10 and uses dual boots where PD in the win 7 partition.
Unless win 10 users themselves offer help then the best thing may be to revert back to the previous os. Reset, reinstall seem to do no good particularly with older 5-6 year old computers. I find no chipset drivers or support for my intel mb for win 10.
It is best to buy a new computer with win 10. If there were any problems in the os before the upgrade then the upgrade is unlikely to fix anything except maybe have more issues. A DxDiag.txt can help here.