To prevent synattack in Windows server 2003 please follow this- Save the following in synattackprotect.reg and double click it to merge- Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters] “EnableTCPChimney”=dword:00000000 “SynAttackProtect”=dword:00000002 “TcpMaxHalfOpen”=dword:00000064 “TcpMaxHalfOpenRetried”=dword:00000050 “TcpMaxPortsExhausted”=dword:00000005 “TcpMaxConnectResponseRetransmissions”=dword:00000003