Remove-LegacyBoot.ps1

<#
.DESCRIPTION
  Powershell script to remove DHCP policies that allows Legacy BIOS based network booting (PXE) based upon information sent by client detailed in RFC 4578 (https://tools.ietf.org/html/rfc4578)
.PARAMETERS
  None - execute directly from Powershell
.VERSION
  1.0
.AUTHOR
  James Pettigrove
.COMPATIBILITY
  Windows 7, Windows 10
.RELEASE DATE
  06/04/2017
.NOTES
  v1.0, 20170401 - Initial Version
#>

$dhcpServers = Get-DhcpServerInDC

$className = "PXEClient(Legacy BIOS)"

$policyName = "Legacy BIOS"

[array]$dhcpScopes = (Read-Host "Enter DHCP Scopes (separate with comma) to remove Legacy BIOS boot option").split(",") | %{$_.trim()}

foreach ($dhcpServer in $dhcpServers) {

    foreach ($dhcpScope in $dhcpScopes) {
        Write-Host -ForegroundColor Yellow "Removing $policyName from $dhcpScope"
        Remove-DhcpServerv4Policy -ComputerName $dhcpServer -ScopeId $dhcpScope -Name $policyName
    }
}