My internet connection doesn't work after a few hours

[KrabbytheKat]

A few months ago I had a registry problem with my computer, I couldn't open any folders without getting error messages. So I decided to reformat my computer recently, the first time none of my data files got deleted but the registry problem was removed. Unfortunately this cropped up several other problems. The first being that nearly all the programs on my comp. didn't work, although that was to be expected. I decided to simply deal with the problem and just reinstall programs that wouldn't work. Then only a few days after my reformatting, my internet connection would randomly stop working. That is to say, the icon that indicates there was a connection was still there, my network appeared to be working, but I would get the 'Page could not be displayed' in IE, and my MSN messenger would disconnect. After a few minutes it seemed like nothing had happened and I could mysteriously connect again. Unfortunately the problem would arise up at around the same time every day. So after a while I got irritated and did System recovery removing all data files. This appeared to had solved the problem, but its come again, and its worse. When my internet connection 'dies' and I try to reconnect only a few minutes later, it gives my many different messages. First it says there aren't enough system resourses, then it'll say the phone book couldn't be accessed, and then the modem isn't working properly (although it is working fyne because another person uses the same connection and they've had no problems of this sort). Either it will begin to work again after 20 mins, or i'm forced to restart because not only does my internet connectino no longer work, I can't start up my music- i'll get some message about there not being enough resources available-, and task manager will not open. I'd like to know WHY my computer is doing this and what, if anything, can be done to solve this problem?