PowerShell script designed to run at the machine-level to re-enable troublesome add-ins that often get disabled by Office. By default this script is looking for add-ins that relate to HP Interwoven WorkSite.

Enable-DisabledOfficeAddins.ps1

<#
.SYNOPSIS
Enable-DisabledOfficeAddins.ps1 - Enable specific Office add-ins

.DESCRIPTION 
Re-enables specific Microsoft Office add-ins that are:
    1. Listed in Disabled Items
    2. Disabled in COM Add-Ins

This is designed to re-enable troublesome add-ins that often get disabled by Office. In this case,
it's add-ins for the HP Interwoven WorkSite EDMS product.

The best use for this is to add a scheduled task that runs every 15 minutes or so. Note that the Office application
in question also needs to be restarted for the add-in to load again. 

You could also potentially attach a trigger to the following Event Log events:
-Application Log    EventID 1000  Source "Application Error"
-Application Log    EventID 59  Source "Outlook" - OL2013 logs this event when it disables an add-in

Update: This was originally written as a user-scope script, but I've modified it to run at the machine level. This makes it
easier to run invisibly as a scheduled task.

.OUTPUTS
Output is to log file in c:\temp\enable_addins.log by default

.LINK
http://daniel.streefkerkonline.com/re-enable-microsoft-office-add-ins-with-powershell/

.NOTES
Written By: Daniel Streefkerk
Website:	http://daniel.streefkerkonline.com
Twitter:	http://twitter.com/dstreefkerk

Change Log
v1.0, 09/04/2014 - Initial version
v1.4, 14/05/2014 - Modified to work against HKLM instead of HKCU
#>

#region Setup
# Match these strings when looking at the disabled items
$disabledItemSearchStrings = "interwoven","worksite"
$comAddInSearchStrings = "imFileSite", "IWRibbon", "zWorkSite", "oUTR02K", "WorkSiteOffice2007Addins" #zWorkSite is a custom add-in we use in-house, the others are standard
$disabledItemsCount = 0
$comAddinsCount = 0
$logFile = "c:\temp\enable_addins.log"

$loadBehaviours = @{ 0  = "Unloaded, Do not load automatically"; 
                     1  = "Loaded, Do not load automatically";
                     2  = "Unloaded, Load at startup";
                     3  = "Loaded, Load at startup";
                     8  = "Unloaded, Load on demand";
                     9  = "Loaded, Load on demand";
                     16 = "Loaded, Load first time, then load on demand"
                   }

#endregion

#region Functions
# Basic logging functionality
Function LogWrite
{
   Param ([string]$LogText)

   Write-Host $LogText
   Add-content $logFile -value $LogText
}
#endregion

LogWrite "---------------start---------------"
LogWrite "Running script at $(Get-Date) on $env:COMPUTERNAME"

#region Delete add-ins from Disabled items in registry
# Recurse through the MS Office registry keys under HKEY_USERS to find "DisabledItems" keys for domain users
$disabledItemKeys = Get-ChildItem -Path "Registry::HKEY_USERS\S-1-5-21-*\Software\Microsoft\Office" -Recurse -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | ? -FilterScript {($_.Name -clike "*DisabledItems*") -and ($_.ValueCount -gt 0)}

# If there was an error reading the registry, or there are no keys found, exit
if (($disabledItemKeys -eq $null) -or ($disabledItemKeys.Count -eq 0)) { exit }

# Loop through they DisabledItem keys for each office application
foreach ($key in $disabledItemKeys) {

    # Loop through the disabled items within each application
    foreach ($disabledItem in $key.GetValueNames()) {
        # Convert the binary-encoded add-in name to text. Remove the null characters to make this a comparable string
        $itemName = [Text.Encoding]::ASCII.getString($key.GetValue($disabledItem)).Replace("`0","")

        # If the name doesn't match one of our search strings, go to the next item
        if (($itemName | Select-String -Pattern $disabledItemSearchStrings).Matches.Count -le 0) { break }

        LogWrite "$itemName matched search pattern."

        # Delete the disabled item value from the registry
        Remove-ItemProperty -Path "Registry::$($key.Name)" -Name $disabledItem

        LogWrite "Removed $itemName from DisabledItems in registry."

        $disabledItemsCount ++
    }
}

LogWrite "$disabledItemscount disabled items re-enabled"

#endregion

#region Enable COM add-ins
$officeUserAddins = Get-ChildItem -Path "HKCU:\Software\Microsoft\Office" -Recurse -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | ? -FilterScript {($_.Name -like "*Addins*") -and ($_.ValueCount -gt 0)}

# If there was an error reading the registry, or there are no keys found, exit
if (($officeUserAddins -eq $null) -or ($officeUserAddins.Count -eq 0)) { exit }

# Loop through all Office Add-ins that match our search strings and don't have a LoadBehavior = 3
foreach ($userAddin in ($officeUserAddins | ? -FilterScript {($_ | Select-String -Pattern $comAddInSearchStrings) -and ($_.Property -eq "LoadBehavior") -and ($_.GetValue("LoadBehavior") -ne 3)})) {

    LogWrite "$($userAddin.Name) LoadBehavior set to '$($loadBehaviours[$userAddin.GetValue("LoadBehavior")])'. Attempting to set it to '$($loadBehaviours[3])'."

    # Set the LoadBehavior to 3 as it should be.
    Set-ItemProperty -Path "Registry::$($userAddin.Name)" -Name "LoadBehavior" -Value 3

    LogWrite "LoadBehaviour for $($userAddin.Name) corrected. Now set to: '$($loadBehaviours[$userAddin.GetValue("LoadBehavior")])'."

    $comAddinsCount ++
}

LogWrite "$comAddinsCount COM add-ins' LoadBehavior value corrected"
LogWrite "----------------end----------------"
#endregion

At line #88 I think you would like to use 'continue' instead 'break'
if (($itemName | Select-String -Pattern $disabledItemSearchStrings).Matches.Count -le 0) { continue }
-> check the next regKey; don't break the whole foreach loop