How can I clean my computer and make it run faster?

I have Windows XP. Sometimes it takes almost a minute to load my homepage. It takes up to a minute to go from one website to the other, and then another 30-45 seconds to load the content on that page. I have made some changes per Google. I have tried typing msconfig in the run box. I checked selective start up so that only select services load. Went into boot.ini and changed timeout to 3 seconds. I have selected adjust for best performance. Deleted all temp folders. My friend who is an IT person, downloaded a registry cleaner, so that has been cleaned. He installed Malwarebytes. It found over 200 problems, and those problems were fixed. The disc cleaner has been performed, and the system has been defragmented. The building that I live in was built back in the 70's. It was not wired for DSL. We eventually had to lower the speed per Verizon to 1 meg, just to get internet service. What else can I do to speed my computer up? I would appreciate any help! Please don't just tell me what to do. Tell me how to do it.