How can I remove a network connection/workgroup in Win 7?

Hi,
I have recently purchased a new laptop with Windows 7 Home Premium and
McAfee antivirus. After I connected the laptop to the local network (don't
remember if I created a network connection in Win 7 in the laptop or .), the
desktop running Win XP Pro, SP 3 lost access to the workgroup (doesn't find
even itself on the workgroup/LAN, while Internet works fine).



After some struggle I found that McAfee has a feature that excludes PC:s not
having McAfee installed on them! Now to my question:



Can McAfee really change settings on other PC:s (?), so that the desktop
loses access to the workgroup, even when the laptop is down? I guess if this
is the case, then it must be because the network connection was created in
the laptop (I am not sure) and if so, I should remove it and re-create it
from within the desktop. Can this be the case? How do I remove the workgroup
in Win 7?



Regards
M Shafaat