Windows Malicious Software Removal Tool x64 - November 2019 (KB890830) -Error 0x800711c7

I'm just going to add a note for those with enough ability to understand what I'm about to say, since I also have a Surface Go device running Windows 10 S and first saw this error code myself when checking Windows Update for a different reason.  This thread told me everything I needed to know, which is that the problem is common and appears to occur only with Windows 10 S since the November MSRT update, which was all I truly cared to know.

I've returned here to explain something I realized myself only after reading the concerns in this thread, since it appears the error code issue continues with the December MSRT release and so will likely continue to receive much concern from those who care enough to use Windows 10 S for its improved security.

The point is that the Windows Malicious Software Removal Tool is described in its knowledge base article as follows.

"Microsoft generally releases the MSRT monthly as part of Windows Update or as the standalone tool. Use this tool to find and remove specific prevalent threats and reverse the changes they have made (see covered malware families)."

If you click the link to the covered malware families above, you'll find there are roughly 300 families detected, but what's more important is that most are either Win32, Win64, Worm or PowerShell types of detection.

To those with even a small amount of knowledge relating to Windows 10 S, you should recognize that since Windows 10 S doesn't allow executable files from other than the Windows 10 Store to operate, nor does it support PowerShell scripts, that means that none of these particular items should even be able to function within Windows 10 S.

The larger question this brings to mind for me is; Why is Microsoft even including the MSRT update in those it provides for Windows 10 S?

I'm afraid I don't have enough time to fully investigate each specific detection to try and discern a reason, but I suspect it might simply be in case a future item added to the MSRT may also affect something Windows 10 S doesn't inherently provide protection from.

For those not following, I'm saying that I don't truly think that the MSRT is (currently) needed with Windows 10 S, so I'm personally not concerned that it's not "installing" (e.g. running) properly.  If Windows Security is indicating that Windows Defender is operating properly, then there's really no reason that the MSRT is needed.

In fact, it's only normal purpose on any Windows desktop or other device is as a sanity check that the installed AV or other security application(s) are performing properly, detecting the most prevalent malware known to Microsoft that are contained within this relatively tiny and fast scanner.

In other words, though the error code display may be disconcerting, I'll simply ignore it myself and assume Microsoft will eventually get around to fixing it when convenient, even possibly by just removing it entirely if there's no reason to support it on Windows 10 S.

Rob

David,

Though I have an extensive background with Microsoft products and security, I'm also currently the target audience for Windows 10 S mode, since my current needs are for light-duty travel using the apps built into a Windows 10 S mode device.  In fact, my own device is precisely the same Microsoft Surface Go that you mentioned, so I'm experiencing the same exact situation and error message as your wife.

The difference is that unlike the typical user here, once I searched and found this thread where others were experiencing the same error with Windows S mode displaying an error attempting to "install" (actually execute) the Malicious Software Removal Tool, I quickly realized the likely reason.  That's because I understand that the MSRT is really nothing more than a sanity check tool that Microsoft delivers to every PC with Windows Update each month, just to confirm that no malware has manged to infiltrate.

The reason the MSRT isn't necessary with S mode is that none of the current 300+ malware items it scans for can operate within Windows S mode, so as Microsoft itself indicated in the following statement from the MSRT support page, there's no reason to run it it on an S mode machine.

Win10-S mode is not supported, there is no added value of running MSRT on this platform. Any install failures of attempting to install the package can be safely ignored.

However, the other reality is that it may be possible that sometime in the future, a flaw is found within S mode that can be exploited, requiring that a new detection be delivered to S mode systems using MSRT.

It's also a fact that everything required to switch out of S mode already exists on a system, so that includes the core MSRT components as well, meaning that Windows Update will inherently attempt to perform these updates, though as we've seen they currently fail likely due to the fact they aren't being delivered via the Microsoft store or with the digital signature required to allow this.

Unfortunately, fixing this issue isn't likely as simple as the failed update itself, since it's a problem embedded within the S mode portion of the operating system.  Since this would likely require significant changes to core portions of the operating system, these can't happen with simple patches and so aren't likely to occur at least until the next major update cycle for Windows 10, which since we're already deep into the version planned for spring release, isn't likely to be included until at least fall.

So rather than completely ignore the problem, Microsoft has provided the information above on the MSRT support page, where more knowledgeable users can find it and relate its true meaning to those like yourself.

The difference is that unlike most, I know the realities behind why this happened and so also understand why it isn't likely to go away quickly.  So I'm not saying I wouldn't like it to myself, only that it's foolish and pointless to complain, since there's simply no way that will change anything in a complex situation such as this.

TO put it more simply, everyone complaining is spitting into the wind, and those complaints won't accomplish anything.  Microsoft is clearly already aware of this problem and will fix it in whatever way they see as appropriate.

In truth, this "failure" is nothing more than a slightly annoying visual anomaly and causes no functional issues for the operating system itself.  That's why I'm not concerned and what I'm trying to get through to intelligent people here, since there's absolutely nothing any of us can do about it, nor in fact that Microsoft can or should beyond what they've already provided with their clear message.

Rob

How about since the update created more problems than it fixed, you put out a hotfix that solves the problem that everyone is dealing with and is unable to solve, rather than sending them all to the same links that don't work for the obvious reason of S mode.

or 

If you're not going to update now, put out a little memo or some such, telling the concerned consumers who have invested money in your products that you will be addressing the issue soon.

I tried the manual download approach - but my Surface laptop, on the Windows 10-S (Safe) setup, would not allow the manual download. It recommended going off the "S" setup, but that is an irreversible change I do not want. 

I am having the same experience on my Surface Go running Windows 10S.

I tried the manual download approach - but my Surface laptop, on the Windows 10-S (Safe) setup, would not allow the manual download. It recommended going off the "S" setup, but that is an irreversible change I do not want.