Windows 7 Upgrade Help

[gettysburgfreak]

So my Asus netbook is running Windows 7 starter. I found a deal online that if your a student you can upgrade to 7 Home Premium for 30 bucks. I used my sisters college email address and got an email with a link to download online. I have tried it three times and still cant get it to work. Each time it takes 8 hours to download. The first time the internet stopped working in the middle of the night, I think that screwed it up. I called Windows help and the guy told me to save it to the C drive. When it finished downloading it said it couldnt find it and didnt work. I am in the process of downloading it for a 3rd time, saving it to my desktop.

Does anyone have any experience upgrading using an online download? If the internet stops working does it really screw up the download?