about 710GUI logon error no 10109.

Dear,

When logon SAP using 710GUI,display following eorror:

NiGetServByName 'sapdp00' not found

Error no. 10109

WSATYPE_NOT_FOUND: the Specified class was not found.

in Logon setting ,connect type is user_defined application server.

the same setting, others machine is no problem.

what reason caused this problem?

please help me.very urgely.

thank you.

pangyanting.