how do i get to the digital download to enter my key

Alright, sometime in these direction you're going to need to create an impulse account, though it will probably prompt you to make one if you haven't already.

On the impulse link I gave you, click the get impulse now button on the left. Then install impulse after you download it and run the program. After it updates itself and opens, hit the list icon in the upper right corner (right below the impulse logo) and select the register product option. It should then prompt you to register a game, so select Sins of a Solar Empire and then enter your CD key.

If your having trouble using impulse, I'm sure their are FAQs on the site, or just ask about your specific difficulty here.

Impulse is your only way. Fortunately Sins does not need the CD in the drive unlike other games, so once you get impulse installed and registered it shouldn't be too much of a hassle of you have a decent internet connection. And even if you don't, it will get installed, it just might take a while.

Hmm, I don't know why you couldn't download it with Internet Explorer, probably because I use firefox. It has a nice download manager so you can see what you're downloading and how fast it is doing so. However, if you are having trouble downloading impulse firefox maybe no better.

One thing I would try is to right click the Get Impulse button on impulsedriven.com and hit the "save link/target as" option. Save it to a location where you find it and hopefully it will download for you.

Ah, you must have a somewhat old computer. Hopefully (Microsofts download links aren't the clearest) this is the .net update you are missing (which is probably the source for a lot of your problems).

^Awesome, glad to hear it. I hope you enjoy Sins as much as I have.