First off, the install program is case sensitive, so if your SQL machine is called SYS-APP-Pamwin and the database is called MyPamwinPlus, make sure you follow the capital letters exactly.

If that doesn't work, the problem is either with SQL server security or with the IIS components. SQL server security should be mixed or SQL only, otherwise M3Pamwin Plus can't connect to it - check this under Enterprise Manager. If the setting looks right, check the password and user name you assigned to M3Pamwin

To check that IIS is working properly, go to Control Panel>Administrative Tools>Internet Information Services. Expand Web Sites>Default Web site>Pamwin plus - a number of files will appear on the right hand side. Find the file called
WebServiceDataAccessLib.asmx - right click on it, and select 'browse'. If IIS is working properly a formatted list of files will appear in a web browser. If this does not happen, check that asp components are properly installed, as follows:

Still in Internet Information Services, right click on the default web site node and select Properties. Click on the Home Directory tab, then click on the 'Configuration' button. In the Applications mapping table, the first few file extensions should begin .asa , .asax , .ascx etc etc. If these extensions are not there, the .NET framework has not installed properly. Uninstall it using Add/Remove Programs then reinstall (including the service pack).