To answer that more thoroughly... is Digital River an authoritative site for distributing Windows 7? We don't know
Are the links legitimate? We know the answer to that, and its yes.
Is it ok to mirror (redistribute on a diff. server) those links? No. Due to the danger of malware injection, at the least.
Would it be trouble to hyperlink to the links? Probably not. We simply don't know. But its on the Internet,
unrestricted. At this point, sites all over the Internet make reference to these links, after years of them being online.
Does it violate EULA? We don't know.
Why would they be there if it does? Well, Digital River sells copies of Windows. How well they protect those copies from arbitrary download would be up to them.
If you don't feel comfortable using DigitalRiver there is always:
How to Replace Lost, Broken, or Missing Microsoft Software or Hardware
Link Removed
If there is a problem putting up DigitalRiver links we can take them down no sooner than we put them up. It would be nice to get clarification from Microsoft, and we could, but it would probably take a very long time, and our connection with them is on the community level.
But seeing as they have a bot that goes about flagging content for DMCA removal, I suspect that, after years, they would have asked Digital River to lock down the content. To give you an idea:
Microsoft asks Gooogle to blacklist Microsoft.com
All of this is speculative.
It is important to us to respect Microsoft's trademarks and copyrights, so if we received a request to remove a link to DigitalRiver we would. As far as any other communication about activation, licensing, etc. these need to be strictly technical, clear, concise, and, of course, we can not give away licenses, or a free copy of X, Y, or Z. The goal of supplying a link to the Digital River files would always be support-based with the assumption that a backup is desperately needed. This is because we know this is a secure distribution point and we don't know why exactly it is open ended to the public, if not to supply a way to download the files knowing for certain they have not been compromised.