Ran all MG tutorials...connection issues continue

I have been actively battling this issue for the last month or longer. About 20% of the time that I am browsing websites, each one of my three browsers will periodically tell me that it cannot connect to the web page. It will say something along the lines that it could not connect to the server. However, if I reload or try it again through various means, it will work. Sometimes it gets bad, so I clear browsing history or try again five minutes later and it will work fine. Earlier on, it used to happen more often, but since then I have completed two malware removal tutorials including your's, and the issue has been less common but still occurs. Sometimes my windows vista folders open very slowly also, but other than that everything is clean and fully operational. I am beginning to think that I might have accidentally deleted registry data while scanning for malware a while back, but then why has the browsing issue been less frequent since it first arose?...it just happened again!