To resolve the issue if FQDN is incorrect :
- Navigate to Administration > vCenter Server Settings... > Advanced Settings .
- Update these attributes with the correct FQDN for vCenter Server:
VirtualCenter.VimApiUrl : https://<vCenter Server FQDN>:443/sdk
VirtualCenter.VimWebServiceUrl : https://<vCenter ServerFQDN>:8443/vws
- Restart the VirtualCenter Management Webservices service. For more information, see Stopping, starting, or restarting vCenter services (1003895).
Note: If your problem still exists after trying the steps in this article, file a support request with VMware Support and note this Knowledge Base article ID (1036541) in the problem description. For more information, see How to Submit a Support Request.
Fix the DNS resolution issues if exists in the environment.
For more information related to Windows XP and Windows 2003 (32bit and 64bit), see the VMware vSphere 5.1 Release Notes.