# Create a list of computers #
$computers = ('computer1','computer2','computer3')

foreach ($comp in $computers){

# Get the active network card, if there is more than one active card you will need to adapt this script #
$Netcard = Get-WMIObject Win32_NetworkAdapterConfiguration -computername $comp | where{ $_.IPEnabled -eq “TRUE”}

# Clear the DNS server ip's so that it can retrieve a fresh list from DHCP #
$netcard.SetDNSServerSearchOrder()

# Enable DHCP on the network card #
$netcard | ForEach-Object -Process {$_.EnableDHCP()}

}