Domain issue with XP pro

I get the following error message when I try to browse the domain from an XP machine.

is not accessible. You might not have permission to use this network resource. Contact the administrator of this server to find out if
you have access permissions.

I had joined my computer to the domain just fine.
I then took the computer off the domain joined it to workgroup and try to join it.

I get the following error message:-

Couldn’t contact the domain. Please check if you
have typed in the correct domain name.

I made sure everything is correct.

Just seems to be XP PRO. Please help…

Thanks,
John