downloads

It sound like you downloaded an adobe dowloader then when you run it, it wants you to login to your Adobe account however it has some problem and thinks your computer is not connected to the internet.  It may be an Adobe air application and something has gone haywire in Adobe Air.  You may want to download the Adobe Air installer. Run it. If it fails try un-installing Adobe Air and try again to install Adobe Air.  If your running windows you may first want to download Microsoft FixIt and see if it list Adibe Air and select to Adobe Air to be fixed by FixIt.

I take it your clock is not set incorrectly? 

If you're running Windows, set your time via the Internet by right-clicking your clock in the Taskar, choosing Set Date/Time, click the Internet tab, click the [Change Settings] button, and then click the [Update Now] button.

-Noel

What OS are you running, specifically?

Did you get the download from Adobe.com?  Even if you did, perhaps you should download it again.  I know it's huge,but it could have been corrupted.

Do you have security software that may be blocking the installer from reaching Adobe.com to verify your Adobe ID?

-Noel

Did you look into Adobe Air I beleive the Adobe Downloader is an Adobe Air application and I have seen the Problem your having which I the was cause by an Air problem it could not login.