Scripts to disable PowerShell Telemetry and Update Check. Scripts add the System environment variables.

Disable-PowerShellTelemetry.ps1

# Disables PowerShell telemetry by setting the environment variable associated with it.
# More info: https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_telemetry

#Requires -RunAsAdministrator

# See this for more info:
# https://gist.github.com/asheroto/5c1711fcbd888c5a621b1ff0b91dfc00
# Bypasses the typical delay experienced with Environment.SetEnvironmentVariable, which can be slow due to its broadcasting a message to all top-level windows.
# These functions offer a more efficient alternative for getting, setting, or deleting environment variables.
function Set-EnvironmentVariable {
    <#
        .SYNOPSIS
        Instantly sets an environment variable in the machine or user environment by updating the registry.

        .DESCRIPTION
        Instantly sets an environment variable in the machine or user environment by updating the registry.

        .PARAMETER Name
        The name of the environment variable to set.

        .PARAMETER Value
        The value of the environment variable to set.

        .PARAMETER Target
        The target environment to set the environment variable in. Valid values are 'Machine' and 'User'.

        .EXAMPLE
        Set-EnvironmentVariable -Name "MyVariable" -Value "MyValue" -Target "Machine"
    #>
    [CmdletBinding()]
    param (
        [Parameter(Mandatory = $true)]
        [ValidateNotNullOrEmpty()]
        [string]$Name,

        [Parameter(Mandatory = $true)]
        [ValidateNotNullOrEmpty()]
        [string]$Value,

        [Parameter(Mandatory = $true)]
        [ValidateSet("Machine", "User")]
        [string]$Target
    )

    $regKey = switch ($Target.ToLower()) {
        "machine" { 'HKLM:\SYSTEM\CurrentControlSet\Control\Session Manager\Environment' }
        "user" { 'HKCU:\Environment' }
    }

    Set-ItemProperty -Path $regKey -Name $Name -Value $Value
}

# Add POWERSHELL_TELEMETRY_OPTOUT environment variable
Write-Output "Adding POWERSHELL_TELEMETRY_OPTOUT environment variable"
Set-EnvironmentVariable -Name "POWERSHELL_TELEMETRY_OPTOUT" -Value "1" -Target "Machine"

Write-Output "Environment variable added successfully."

Disable-PowerShellUpdateCheck.ps1

# Disables PowerShell update check that is performed when PowerShell is launched.
# More info: https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_update_notifications

#Requires -RunAsAdministrator

# See this for more info:
# https://gist.github.com/asheroto/5c1711fcbd888c5a621b1ff0b91dfc00
# Bypasses the typical delay experienced with Environment.SetEnvironmentVariable, which can be slow due to its broadcasting a message to all top-level windows.
# These functions offer a more efficient alternative for getting, setting, or deleting environment variables.
function Set-EnvironmentVariable {
    <#
        .SYNOPSIS
        Instantly sets an environment variable in the machine or user environment by updating the registry.

        .DESCRIPTION
        Instantly sets an environment variable in the machine or user environment by updating the registry.

        .PARAMETER Name
        The name of the environment variable to set.

        .PARAMETER Value
        The value of the environment variable to set.

        .PARAMETER Target
        The target environment to set the environment variable in. Valid values are 'Machine' and 'User'.

        .EXAMPLE
        Set-EnvironmentVariable -Name "MyVariable" -Value "MyValue" -Target "Machine"
    #>
    [CmdletBinding()]
    param (
        [Parameter(Mandatory = $true)]
        [ValidateNotNullOrEmpty()]
        [string]$Name,

        [Parameter(Mandatory = $true)]
        [ValidateNotNullOrEmpty()]
        [string]$Value,

        [Parameter(Mandatory = $true)]
        [ValidateSet("Machine", "User")]
        [string]$Target
    )

    $regKey = switch ($Target.ToLower()) {
        "machine" { 'HKLM:\SYSTEM\CurrentControlSet\Control\Session Manager\Environment' }
        "user" { 'HKCU:\Environment' }
    }

    Set-ItemProperty -Path $regKey -Name $Name -Value $Value
}

# Add POWERSHELL_UPDATECHECK environment variable
Write-Output "Adding POWERSHELL_UPDATECHECK environment variable"
Set-EnvironmentVariable -Name "POWERSHELL_UPDATECHECK" -Value "Off" -Target "Machine"

Write-Output "Environment variable added successfully."