WinTCPKill is a TCP connection killer for Windows 9x/2K. You must be able to sniff traffic of the target - if you are in a switched network you can use ARP Cache Poisoning tools like winarp_sk or winarp_mim (see https://www.arp-sk.org).
923d8a462a5f0fac999c2cbce0fc54dbc03131e7c3825ac2322c9b299d0809d2