Downloading problems

I just received my new Intel iMac computer on Thursday night. On Friday night, it said that I had about 11 updates to install on it, so, I started downloading them. What I'm having problems with is, where I live, I can only get dial-up or satellite......there is no DSL. One of the updates is to upgrade from Tiger OS X 10.4.7 to 10.4.9. I have tried to do that more than once and each time it downloads for hours, and then all of a sudden, it will just disconnect from the internet. I have since tried to do it in smaller steps.....going from 10.4.7 to 10.4.8. I also made it where the computer would never sleep because I thought that might have been what was kicking it off of the internet. I let it download all night last night from about 7:00 p.m., and then I checked it at 7:00 a.m. this morning, and it was still downloading. Well, I checked it again before I went to work, which was a little after 8:00, and it had been disconnected from the internet. I was just wondering if anyone else is having trouble with this same issue. If so, how did you correct it?