Steps to reproduce:
Click Start --> Programs --> Oracle - OraDb10g_home1-->Database Control
This is caused by Internet Explorer Enhanced Security enabled by default in Windows Server 2003. You can tell this is the cause by a popup notification when you open up Internet Explorer that says:
Microsoft Internet Explorer's Enhanced Security Configuration is currently enabled on your server. This enhanced level of security reduces the risk of attack from Web-based content that is not secure, but may also prevent Websites from displaying correctly and restrict access to network resources.
To resolve, choose from one of the following methods:
1. Remove it via Add/Remove Programs under Add/Remove Windows Components
2. Disable it for Administrators or only for Users by clicking the Details button in the Add/Remove Windows Components Wizard, or
For additional information on Internet Explorer's Enhanced Security, see: http://support.microsoft.com/kb/815141