SCM: That problem sure is related to that PC, this tracert is from 2nd PC
Tracing route to us.battle.net [12.129.242.40]
over a maximum of 30 hops:
1 <1 ms <1 ms <1 ms ipcop.rebelnet-nz.com [192.168.2.1]
2 49 ms 100 ms 99 ms 192.168.1.253
3 22 ms 22 ms 23 ms 68.16.69.111.dynamic.snap.net.nz [111.69.16.68]
I would guess you are in the South Island? Also that looks like a Thomson modem/router giving that false quirky 99ms reading there (nothing to worry about, just a quirk of the Thomson's).

