SP2 or low quality component

After SP2 was installed in my computer, my compute had been working properly for a while. I can play movie and music and send fax by Just the Fax. Only when I installed software called DOWNLOAD ACCELARATOR, did my computer appear BLUECREEN. I just wonder what cause the blue screen, SP2 or low-quality hard components (some experts say I can not use WINDOW XP due to my low-quality hard components).

Thanks for your time and consideration.