Dave: Are you logged in as or with administrator
prvilages? and have you tried this exactly
!: start \run \cmd enter ipconfig /release then type
ipconfig /renew
check to see all settings by typing ipconfig /all
this will show all ip/gateway dns mac address ect
you have probably already tried this and if this dont work
you can try this
if it worked ok anytime in the last 8 weeks
you could try running system restore to a restore point
when it did work.
You can try this by going to
start\programs\accessories\system tools\system recovery
and follow prompts. there is an explanation and fix for
this to be sure but this might be alot easier.
good luck