There is one other aspect to look at that might also cause this issue; and that is your Power Supply Unit. The best way to find this information is to physically look at the sticker on the side of the unit inside the rig. You should be looking for a minimum of around 400watts.

Another thing to try is to:
Open an Internet page > Tools > Internet Options > Delete Cookies > OK > Delete Files > tick the box 'Delete all offline content' > OK > Content > clear SSL State > OK.

By the way, how often do you defragment your Hard Drive?
A fragmented Hard Drive will be 'slower' too.

Also try:
Go into Internet Options again, this time, click on the Programs tab > Manage Add-ons. In here look for any BHO's, or Browser Help Objects; particularly, one called 'SSV Helper Class', and disable it!
Reboot your system and see if it is 'faster' at responding.

These are just some of the things you could try!!