Windows And Oracle Problem

Hi...

Our server is Windows server 2003 64 bit on which SAP IDES 6.0 is there.

its working fine. then we have remove Domin through RUN>DCPROMO command so all my user has been removed so i have again created windows users.

after that all my service working fine with Dispatcher.

but when i am trying to logon with SAPLOGON its giving "Application server shutdown" and then Dispatcher service is getting stop.

then i am trying in SQL Plus with Username/Pwd it is giving following error.

"Oracle not available.

Shared Memory realm does not exsist."

i have tried with already available forums but its not working.

Following group are also not available in windows group

ORA_XEP_DBA

ORA_XEP_OPER

SAP_LocalAdmin

SAP_XEP_LocalAdmin

SAP_XEP_GlobalLocalAdmin

i have added in Oracle forum but not helpful so i think windows users can help

Kindly help.