Event id 9175 & 1005

[zercon]

Hi all
My exchange server 2000 have problem.Store.exe stop service and event log show message
Source:Msexchange
Category:MAPI Session
Event id: 9175
The MAPI call 'OpenMsgStore' failed with the following error:
The Microsoft Exchange Server computer is not available.
Either there are network problems or the Microsoft Exchange Server
computer is down for maintenance.
The MAPI provider failed.
Microsoft Exchange Server Information Store
ID no: 8004011d-0526-00000000

AND

Source:Msexchange
Category:Monitoring
Event id: 1005
Unexpected error <<0xc1050000 - Network problems are preventing
connection to the Microsoft Exchange Server computer. An unexpected,
unknown error has occurred. Microsoft Exchange Server Information
Store ID no: 80040115-0514-000006bf>> occurred.


Have any idea for help me.

thank you.