If the standard yellow box in the top right isn't appearing in a WSS site, then you need to enable searching. To enable the search, you must do a number of things:

• Use Microsoft SQL 2000 SP3 or later, rather than MSDE. Also, ensure that the default "Full-Text Search" [FTS] components are installed, and the MSSearch service is setup and marked to auto-start and run under an account that has permissions to the database. Also check for any MSSearch errors in the event log.
• Search must be enabled in SharePoint Central Administration (Go to Windows SharePoint Services, then under "Search Settings and Indexed Content" click on "configure full-text search" and tick "Enable full-text search and index component"). Note: Sometimes un-ticking and re-ticking this option can help.