Control maximum size of baseline file cache
Verified with Windows 11 25H2 — updated on July 30, 2026
Supported on: Windows Installer v3.0
Path in the GPO console
Computer Configuration\Administrative Templates\Windows Components\Windows Installer Description
This policy controls the percentage of disk space available to the Windows Installer baseline file cache. The Windows Installer uses the baseline file cache to save baseline files modified by binary delta difference updates. The cache is used to retrieve the baseline file for future updates. The cache eliminates user prompts for source media when new updates are applied. If you enable this policy setting you can modify the maximum size of the Windows Installer baseline file cache. If you set the baseline cache size to 0, the Windows Installer will stop populating the baseline cache for new updates. The existing cached files will remain on disk and will be deleted when the product is removed. If you set the baseline cache to 100, the Windows Installer will use available free space for the baseline file cache. If you disable or do not configure this policy setting, the Windows Installer will uses a default value of 10 percent for the baseline file cache maximum size.
Registry
Software\Policies\Microsoft\Windows\Installer MDM / Intune (CSP)
./Device/Vendor/MSFT/Policy/Config/ADMX_MSI/MSI_MaxPatchCacheSize Microsoft Learn documentation Mapping data: Microsoft Learn (CC BY 4.0)
Export Builder
BETAConfigure the state, scope and options, then generate .reg, PowerShell, Intune and SCCM outputs — or add the setting to a multi-setting collection.
These exports write the registry — this is not a managed GPO. ⓘ
.reg file
Windows Registry Editor Version 5.00
; Exported from gporais.com
; Policy: Control maximum size of baseline file cache
; State: Enabled
; Supported on: Windows Installer v3.0
[HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\Installer]
"MaxPatchCacheSize"=dword:0000000aMore formats (PowerShell, Intune, SCCM)
PowerShell
# Exported from gporais.com
# Policy: Control maximum size of baseline file cache
# State: Enabled
# Supported on: Windows Installer v3.0
$path = 'HKLM:\Software\Policies\Microsoft\Windows\Installer'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'MaxPatchCacheSize' -Value 10 -Type DWordIntune XML
OMA-URI: ./Device/Vendor/MSFT/Policy/Config/ADMX_MSI/MSI_MaxPatchCacheSize
Data type: String
Value:
<enabled/>
<data id="MSI_MaxPatchCacheSize" value="10"/>Intune Remediation
# === Detection script ===
# Exported from gporais.com
# Policy: Control maximum size of baseline file cache
# State: Enabled
# Supported on: Windows Installer v3.0
function Test-RegistryValue {
param(
[Parameter(Mandatory = $true)][string]$Path,
[Parameter(Mandatory = $true)][string]$Name,
[object]$Expected,
[ValidateSet('String', 'DWord', 'MultiString')][string]$Kind = 'String',
[switch]$Absent
)
try {
$item = Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction Stop
} catch {
return $Absent.IsPresent
}
if ($Absent.IsPresent) { return $false }
$actual = $item.$Name
if ($Kind -eq 'DWord') { return ([int64]$actual) -eq ([int64]$Expected) }
if ($Kind -eq 'MultiString') {
$actualValues = @($actual)
$expectedValues = @($Expected)
if ($actualValues.Count -ne $expectedValues.Count) { return $false }
for ($i = 0; $i -lt $expectedValues.Count; $i++) {
if ([string]$actualValues[$i] -ne [string]$expectedValues[$i]) { return $false }
}
return $true
}
return [string]$actual -eq [string]$Expected
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Windows\Installer' -Name 'MaxPatchCacheSize' -Expected 10 -Kind DWord)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Control maximum size of baseline file cache
# State: Enabled
# Supported on: Windows Installer v3.0
$path = 'HKLM:\Software\Policies\Microsoft\Windows\Installer'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'MaxPatchCacheSize' -Value 10 -Type DWordSCCM scripts
# Exported from gporais.com
# Policy: Control maximum size of baseline file cache
# State: Enabled
# Supported on: Windows Installer v3.0
# SCCM Configuration Item guidance:
# Create a Configuration Item of type "Setting: Script".
# Discovery script: use the Detection script below.
# Remediation script: use the Remediation script below.
# Compliance rule: the Discovery script output equals 'Compliant'.
# === Detection script ===
# Exported from gporais.com
# Policy: Control maximum size of baseline file cache
# State: Enabled
# Supported on: Windows Installer v3.0
function Test-RegistryValue {
param(
[Parameter(Mandatory = $true)][string]$Path,
[Parameter(Mandatory = $true)][string]$Name,
[object]$Expected,
[ValidateSet('String', 'DWord', 'MultiString')][string]$Kind = 'String',
[switch]$Absent
)
try {
$item = Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction Stop
} catch {
return $Absent.IsPresent
}
if ($Absent.IsPresent) { return $false }
$actual = $item.$Name
if ($Kind -eq 'DWord') { return ([int64]$actual) -eq ([int64]$Expected) }
if ($Kind -eq 'MultiString') {
$actualValues = @($actual)
$expectedValues = @($Expected)
if ($actualValues.Count -ne $expectedValues.Count) { return $false }
for ($i = 0; $i -lt $expectedValues.Count; $i++) {
if ([string]$actualValues[$i] -ne [string]$expectedValues[$i]) { return $false }
}
return $true
}
return [string]$actual -eq [string]$Expected
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Windows\Installer' -Name 'MaxPatchCacheSize' -Expected 10 -Kind DWord)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Control maximum size of baseline file cache
# State: Enabled
# Supported on: Windows Installer v3.0
$path = 'HKLM:\Software\Policies\Microsoft\Windows\Installer'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'MaxPatchCacheSize' -Value 10 -Type DWordBuilding a multi-setting collection? Add this setting and generate combined .reg / PowerShell / GPO scripts.