who is at fault, my pc or my isp

ive downloaded a lot of software that wwould speed up my connection and surfing in the internet. but it seems my browsing and searching is still slow. i have 56kbps modem 126ram memory ,duron850 in my pc… what really causes slow surfing using dialup. they say it could be isp congestions, some say i have substandard pc. which is to blame? please enlighten me thanks again friends