dhcp problem

In the Phy Dept, there was an issue with a new Dell desktop with a wifi dongle not getting an ip address from the wireless router. Both were Netgear products, working fine on an identical machine on the next table. WG 111 (v3) Netgear wifi USB dongle, router was a Netgear WPN824.

After many tries with WinXP "repair" and the command-line

ipconfig /release
ipconfig /renew

and other such stunts, even a wired connection to the router failed, and pings showed a strange character in the destination's place,

Pinging <strange wing-dings character> with 32 bytes of data:

Finally it was wiped and the dell recovery CD was used to re-install WinXP, then everything started working again.