Perhaps not the the best solution, but have you tried updating to the hosts file ( %windir%\system32\drivers\etc\hosts ) on the XP workstation?
* requires server to be on fixed IP address
* only resolves situation one way (allows XP workstation to address server by name).
* it is a per-workstation setting -- you need to do this on *each* workstation where names aren't resolving

>Thanks for the response.
>
>I guess it's not resolving. I can ping with ip but not name. How to make it resolve?
>
>Alex
>
>>Is the DNS resolving?
>>
>>>Hi,
>>>
>>>At home I reinstalled windows server 2008 r2 in our server after difficulties and am now trying to replicate the previous environment which includes using a workgroup instead of domain. However, the server and a windows xp machine cannot see each other. A windows 7 machine can see both the windows 2008 r2 server and the xp machine.
>>>
>>>What may be the reason?
>>>
>>>TIA,
>>>
>>>Alex