Why wouldn't a broadband (cable, ADSL) connection work? Dial-up modems are soooo outdated. Can you provide the link where they say that? Or don't you have broadband at home, so dial-up is the only option, also on your desktop? Then downloading all the stuff they want you to read and view will take a lot of time, I'm afraid.
The obvious advantage of a netbook is its price and portability. But for not much more you'll find a laptop with a much better keyboard and much larger screen and a much better performance.
I'd start with using your desktop as the primary machine to study (for ease and performance and screensize). Then, if you feel it's a good idea to study elsewhere also, use a USB-stick to view all the stuff you downloaded on a more portable device. That could be a netbook or a laptop or even a tablet if you can get that stuff onto it. You won't be able to use the dial-up connection anyway outside your house.
Kees
Hello,
I am about to begin online college courses and was considering a netbook (looking at multiple versions of asus eee) for portability reasons. The college i'm enrolled in requires 56k baud modem which is not included on any of the netbooks i've seen. Does anybody have any advice on if it is a good idea to buy an external modem for this kind of device or I should just give up the netbook idea and stick to taking my classes on my pc. I am specifically interested in a netbook because of the price point but it just may not offer what i'm looking for. I'm not very tech minded so would love advice from anyone who has experience with this type of issue. Thanks so much!

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