You may run across the need to restart Excel Services in SharePoint 2007 if the Excel Services web parts are not rendering. Typically, restarting the service can fix this issue. This is done through STSADM.

Stsadm –o enumservices will give you the service type information, which is the stuff in the quotes below. I created 2 BAT files in the same directory as STSADM to keep from having to retype all of this:

StopExcelServices.bat
stsadm -o provisionservice -action stop -servicetype "Microsoft.Office.Excel.Server.ExcelServerSharedWebService, Microsoft.Office.Excel.Server, Version=12.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c"

StartExcelServices.bat
stsadm -o provisionservice -action start -servicetype "Microsoft.Office.Excel.Server.ExcelServerSharedWebService, Microsoft.Office.Excel.Server, Version=12.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c"