Fix Post-Demotion DC Slowdown

After demoting and removing our old Windows domain controller/DNS server (192.168.1.3), file access over our Windows file share has become painfully slow whenever that machine is powered down. A quick... (Budget: £20 - £250 GBP, Jobs: Active Directory, DNS, Network Administration, Network Security, Powershell, System Administration, Troubleshooting, Windows Server)