Microsoft has been flooded with complaints from hundreds of disgruntled university bods who have struggled to download or successfully install Windows 7 files supplied by Digital River.

As we reported last week, many UK-based university staff and students who stumped up £30 for Microsoft’s Windows 7 academic offer were grumbling the download wasn’t working for them.

Since then, academic customers trying to take advantage of Redmond’s $29.99 Windows 7 upgrade offer to students in the US have also been hit with problems once the software was downloaded from the Minneapolis-based Digital River’s website.

We repeatedly contacted both Microsoft and Digital River last week to find out what had gone wrong with the downloads, after users began reporting problems within hours of the official consumer launch of Windows 7. However, neither company got back to us with an explanation.

Microsoft has, however, since posted a customer response on its “answers” website, which appears to be about as close to an official statement as we can expect on this issue.

According to the post, users weren’t only hit with problems trying to download the software. Some managed to grab the necessary files via Digital River’s site, only then to be faced either with incompatibility issues or, worse still, having errors spat out when they attempted to unpack files from the download.

“Rather then providing an ISO file for students to download, they [Digital River] provided an unpacker and a couple of .BOX files which must be unpacked into a disk image,” a Windows 7 customer told us. “It seems that users with x86 systems cannot unpack the files for an x64 download, the unpacker halts with an error.”

And The Register has heard from unhappy academics in Australia too.

“Basically, when running the setup file to ‘unpack’ the two .BOX files (note that they have chosen to use a non-standard format, rather than providing an ISO that everyone can work with), the installer fails and throws an ‘unspecified error’ message,” one Oz reader similarly reported. “This is unacceptable, and personally I’m hoping for a solution, or my money back.”

There's plenty more gripes about this problem here as well.

Microsoft said in its post that it and Digital River were “investigating” that particular problem. In the meantime it’s telling users that the likely cause relates to incomplete files becoming corrupted on their computers.

“Users encountering this issue should try and re-download the files by logging into your [Digital River] order,” said Microsoft.

Customers have also hit snags when purchasing a 64-bit upgrade to Windows 7 when running the 32-bit version of Windows Vista on their PCs. It would seem that despite the software requiring a clean install rather than a straightforward upgrade, many perplexed punters were still able to buy the software via Digital River, without being warned that their current OS was unable to perform the upgrade.

Microsoft said affected users would be able to refund their 64-bit Windows 7 and re-order the 32-bit version of Windows 7 in order to qualify for the academic upgrade offer.

Alternatively, those 32-bit Vista customers who want the 64-bit version of Windows 7 will need to wait for Digital River to ship out the backup DVD, in order that they can do a fresh install of the software.

It's fair to say that Digital River has made a complete hash of adequately explaining what users can and can't do with the upgrades on offer. Add to that the fact that the supplier failed to provide a simple .ISO file to customers downloading the software and it's of little wonder that so many customers who paid up for the Windows 7 academic offer in good faith are struggling to get their hands on the OS. ®