So I'm new here, yay..

I just wish I was posting under better circumstances. My fiance and I have just gotten Kobo eReaders, but mine has been an expensive paperweight because Adobe Digital Editions doesn't want to function on my computer! I'm copy/pasting from where I've posted on other sites, so if the formatting is a little wonky, please forgive me. I hope someone here can help me though, as I seem to be the only one on the planet experiencing this...
I'm getting an IO Error on Network Request. I see threads in various places on this going back 3 years and no solutions on hand to try. I've completely turned off Windows Firewall. Avast and Ad-Aware are turned off. Port 80 is open. I can physically copy and paste the URL it gives me in the error message and pull up the .epub file. Heck, I can read the whole thing from my computer if I want! There is NOTHING blocking Adobe. But Adobe keeps saying theres a network error, and as a result, is refusing to "unlock" the ePub for use. Adobe Support told me that the Kobo isn't supported... buuut, the link he sent as proof showed that the Kobo is, in fact, a supported device. Oh, and he closed my ticket without fixing the issue. Fantastic. So, what now? And heres the kicker- my big, fancy gaming computer stumbles on this task, but my fiance's gimpy old laptop in the next room works FINE. Kinda irritating, and I hate not being able to figure this out on my own. Here is the error message in its entirety:
IO Error on Network Request.
Please check your network connection and try again.
Network Path:
http://ecimages.shortcovers.com/46b...8d02cec274.epub
Event Detail:
Error #2038
Thanks in advance!