One ping window will not do it. I had to open about 10 - 15 windows, each with the max packet size, to bring down my friends machines. They didn't really even die then, just got so slow they had to reboot to do anything. We were all testing each other on a 10BT network just for fun, this was not a malicious attack or anything. These are on Win98 machines, PIII 500 with 128 MB RAM.