Access Permission

I have setup a home network with my main PC with XP Pro
and my notebook with XP home. After allowing guest
access on the mainpc, on the notebook a get the password
window and i put the password and then I get the message
that I dont have permission to access the mainPC from the
notebook.

I am stumped ... I have made so many configuration
changes but I still cannot access the MainPC from the
notebook.

But, I can access the notebook from the mainPC ... I
don't understand.

Can someone please help me to have access on both systems.

Regards
Kamil