This will be tough for me to explain...
When you have DSL, NOTHING has to be installed. Windows has the capabilities built in. Lets say you have YahooATTWhatever it is now. You don't need all of their garbage software installed. You only need to be set up at the modem(and the router, if you have one... Do you???). I would imagine your modem is already set up, so all you should have to do is plug in, open Internet Explorer, and you should be fine.
Now let's work on your "crashed" computer
Can you give a little more info on what it is doing? What is the exact message? You may be able to fix the MBR or do a repair install and be just fine.