Run Native Access.
 
Komplete Kontrol and Reaktor 6 Player also had updates.

In case it's helpful to somebody, let me relate the troubles I had installing this update.
 
I just today realized that I've been unable to update Kontakt since October. Looking in the installation log, I saw that the last 3 updates have all failed in the same way. I don't know if I closed Native Access without noticing the failure message, or just decided to put off the mystery for another day.
 
In each case, the message said it could not delete the previous version. Even after rebooting and running NA as Administrator. The log contained only this cruelly unhelpful line: "Caught installer exception: 'Uninstall error'". Duh.
 
I attempted to manually uninstall Kontakt, but Windows reported "An error occurred while trying to uninstall Native Instruments Kontakt 5. It may have already been uninstalled." Windows was lying. I opened Kontakt to check, and sure enough, it's still there. So Native Access couldn't delete it and Windows claimed it was already gone. Yikes.
 
I then followed the instructions in this knowledgebase article, which provides a utility for the brute-force deletion of NI products from the registry. Only then, with all parties finally agreeing that Kontakt was indeed gone, was I able to do a full install of Kontakt 5 and all's well. We'll see what happens with the next dot-release.

It was sounding like a registry issue from your description. Sometimes clearing the registry of all mention helps in remedying things like this.

P.S. I attempted to update Reaktor and it failed in the same way. Unfortunately, the previous fix did not help. It just changed the failure message to "Installing Reaktor 6 failed: installation broken, please check the configuration".
 
Some day, I'm going to have to take a look at Reaktor and see what it's about. Not today, though.
 
Update: I was able to re-install Reaktor by removing Reaktor 5 as well.

You need to delete the installation path in the registry as it points to a non existent install msi file as the packages are installed via an ISO file.
 Just search for example "Komplete Control" in regedit and you should eventually find something like this:
 
[HKEY_CLASSES_ROOT\Installer\Products\C571B2D6D077884458D1763449EAD79F]
"ProductName"="Native Instruments Komplete Kontrol"
"PackageCode"="9245B32F2B4F0A84AABC3D3F5712DB09"
"Language"=dword:00000409
"Version"=dword:01090001
"Assignment"=dword:00000001
"AdvertiseFlags"=dword:00000184
"InstanceType"=dword:00000000
"AuthorizedLUAApp"=dword:00000000
"DeploymentFlags"=dword:00000002
"Clients"=hex(7):3a,00,00,00,00,00
[HKEY_CLASSES_ROOT\Installer\Products\C571B2D6D077884458D1763449EAD79F\SourceList]
"PackageName"="Komplete Kontrol Setup PC.msi"
"LastUsedSource"=hex(2):6e,00,3b,00,31,00,3b,00,43,00,3a,00,5c,00,2e,00,6e,00,\
  61,00,74,00,69,00,76,00,65,00,2d,00,69,00,6e,00,73,00,74,00,72,00,75,00,6d,\
  00,65,00,6e,00,74,00,73,00,2e,00,74,00,6d,00,70,00,5c,00,6d,00,69,00,61,00,\
  37,00,43,00,38,00,32,00,2e,00,74,00,6d,00,70,00,5c,00,64,00,61,00,74,00,61,\
  00,5c,00,00,00
 
Just Export the top level hive just in case [HKEY_CLASSES_ROOT\Installer\Products\C571B2D6D077884458D1763449EAD79F]
and then delete it the install will then work.
 

werewindle
[HKEY_CLASSES_ROOT\Installer\Products\C571B2D6D077884458D1763449EAD79F]
and then delete it the install will then work.

I deleted this key but installation (of NI Driver) still fails with the same error msg: "installation broken, please check the configuration".
 

N.I. ---- never seems be able to get out of it's own way.

I have checked the registry, services , devices and there is no mention of a NI driver apart from the hardware drivers for Komplete keyboards. Suggest checking "Device Manager" to see if anything has an orange triangle indicating a problem. Deepening on what version of Windows either go to Control Panel and select Device Manager or click on settings and type Device Manager in search box. Windows will automatically expand the tree if there is a warning.
If nothing there try install again note the time and check Event Log for all windows logs for same time for any entry.
Event viewer can be found by clicking on Administrative tools or typing in search box.
This should give a clue to what has happened because if you submit a ticket to NI all they'll say is uninstall Kontakt which you can't do as it was created with an ISO file.  Post details for what you find and I'll see if I can help.