Major sluggish laptop

Hello,

i have a Windows vista Acer Aspire 6530 laptop i've been using it for a while now about 6 yrs i know it old but i really dont think it can be acting like this i mean i have enough graphic capacity to play DmC and Skyrim at very high setting without having to sacrifice performance but now i cant even watch youtube videos, i have triewd everything scanned for anyhting you can think of, i tried 3 different tune up brands none succeful i mean i started writing this when i was 10 now im 89, thats how slow it is now i have enough ram to run windows 8 smoothly and have over 90GB of free space i have and AMD TURION Dual-core processor with hyperthreading my graphics card is some AMD thing have all windows updates... i just dont know whats wrong.... or is it time to say good bye to my laptop? please help me, thank you.  

P.S. idk just out of the blue whenever i try switching to 2 cores it only gives me the option of 1... weird huh?