Category Archives: Windows

Stuff about Microsoft’s answer to elevator music

“Invalid provider type specified” CryptographicException when accessing the PrivateKey property of a certificate in C#/.Net

We recently encountered this in a production environment: A customer had installed a new certificate, and this exception began showing up in the logs. Luckily, the application was smart enough to at least fall back on using the previous (not yet expired) certificate, so no downtime occurred. Turns out the customer had been provided with […]

The trust relationship between this workstation and the primary domain failed

So, you resurrected a VM from the cold, damp crypts of the deepest backup dungeons, and now you can’t log in because the VM doesn’t trust the domain server anymore? That’s alright. The Windows Domain will rotate its keys from time to time, and an offline VM snapshot will not know about it. You don’t […]

Who deleted the files from the Windows file server?

Classic whodunit – the file is gone. Who deleted it? Well, unless you’ve already prepared for this, Windows has no log for you. Sorry. The good news is that this is an excellent time to prepare for the next time. So let’s do that. Enable the auditing of file operations to the Windows Event Log […]

Enable remote management of Windows Server Core and Hyper-V Core

This is a reference for the commands to enable the firewall rules necessary to remotely manage Windows Server Core and Hyper-V Core. I keep having to look these up… Enable-NetFireWallRule -DisplayName “Windows Management Instrumentation (DCOM-In)” Enable-NetFireWallRule -DisplayGroup “Remote Event Log Management” Enable-NetFireWallRule -DisplayGroup “Remote Service Management” Enable-NetFireWallRule -DisplayGroup “Remote Volume Management” Enable-NetFireWallRule -DisplayGroup “Remote Scheduled […]

Forcing Cygwin to create sane permissions on Windows

If you use Cygwin to mainly manipulate files in your regular Windows filesystem, under /cygdrive/…, you have probably seen this message more than a few times: “The permissions on <node> are incorrectly ordered, which may cause some entries to be ineffective” You have also likely seen “NULL SID” as the top entry in permission lists. […]

Using external Certificate Authority certificates in a restricted or closed environment

In this example, we’ll be using a wildcard certificate from Let’s Encrypt, obtained through their recently released wildcard certificate offering. What we’re doing The use case is that we want, for one reason or another, to use this certificate in an environment that does not have unrestricted internet access, such as a health institution or […]

How to deal with error 0xC03F6506 when upgrading stubborn Windows 10 Home Edition machines to Pro using a VLK

So, the machine auto-activates Windows 10 Home Edition at install time. No prompts, no nothing. You insert the generic upgrade key, and it throws an unhelpful error message back at you: Error code 0x83FA067 means exactly the same thing, as does 0xC004F069. This probably surprises nobody, but trying again, as the above message suggests, will […]