Assuming your PC is free of any nasties slowing your connection down, then I would recommend leaving well alone. Programs offering extra speed never worked for me and often caused more problems than they reported to solve. OS tweaks often have the same negative effect.
I am on dial up freeserve because I cannot get broadband. If you want pages to load faster download and instal Opera Web Browser. It works alongside IE but loads a lot quicker and when you press the BACK button it's instantanious. Best thing I ever downloaded and no they are not paying me to sat that. click here choose the java download 15.7mb. Good Luck
I have Broadband but people I know who have installed ONSPEED have said it genuinely makes a big difference. It can be found on many magazine discs for a trial period then costs £25 pa. The theory behind it is that they intercept your incoming and reduce it's size then your machine increases it again.