How to delete upgrades in Windows Server Update Services (WSUS)

Because parsing only happens once, and WSUS does not know what “Upgrades” are without having installed KB 3095113, it incorrectly identifies the upgrade as a regular update and saves it to the SUSDB as such.  In order to remedy this, you must perform the following sequence of steps on the WSUS servers as specified in the table below (where "USS" represents "upstream server"):

Action	Where to perform
1.       Disable the “Upgrades” classification	USS or Standalone WSUS
2.       Delete the previously synched upgrades	All WSUS (start with topmost server)
3.       Enable the “Upgrades” classification	USS or Standalone WSUS
4.       Perform full sync	USS or Standalone WSUS

Some workarounds propose that you delete these entries from the SUSDB via SQL queries, but we do not recommend directly modifying database content.  The supported way to remove update content is with PowerShell commands [from an elevated session] as described below.  Again, be sure that you perform the deletion step on the WSUS server that is highest in your hierarchy first, and then work your way down; otherwise, your deletions may be replaced by the USS on the next sync attempt.

// disable Upgrades classification on local WSUS server
Get-WsusClassification | Where-Object -FilterScript {$_.Classification.Title -Eq “Upgrades”} | Set-WsusClassification -Disable

// delete all update content on the current server belonging to the 1511 release
$s = Get-WsusServer

$s.SearchUpdates(“version 1511, 10586”) | foreach { $s.DeleteUpdate($_.Id.UpdateId) }

// enable Upgrades classification
Get-WsusClassification | Where-Object -FilterScript {$_.Classification.Title -Eq “Upgrades”} | Set-WsusClassification

// perform full sync
$sub = $s.GetSubscription()
$sub.StartSynchronization()


Source: https://blogs.technet.microsoft.com/