Weird Ping Issue with local network

[Frozen8950]

ok i have this network with 9 computers.

everyone can see everyone on the network fine, except Computer 2 can not see computer 3 and vice versa if you try and ping them it says it can not find the host.

you can ping 2 or 3 from any other computer fine.

I took 3 computers and did a ping -t Computer2 and all 3 of them would time out at the same time over and over.. sometimes compleating for about a 30% packet loss

i took the same 3 computers and pinged another computer on the network.. 100% success for over 5 minutes.. This leads me to belive there is somthing wrong with Computer 2 some how?

could this be the cause of all my network woes?