Adding an extra server to an existing farm

Here’s how that can be done:

1. Install Windows Server 2003 R2
2. Install IIS 6.0 
3. Install .Net 2.0 and .Net 3.0
4. Fully patch the server with the respective service packs and security updates
5. In Internet Information Services Manager remeber to allow ASP.Net in the Web Service Extensions section. 
6. Join the server to the domain where the rest of the farm belong to, if you haven’t already done so
7. Add the MOSS installation account to the local administrators group.

Install MOSS and join the server to the existing farm

1. Install using the MOSS installation account
2. Start MOSS Setup, enter your license key and accept the license agreement
3. Select Advanced and Complete install
4. Run the SharePoint Product and Technologies Configuration Wizard
5. Connect to an existing farm
6. Enter the MOSS database server end click Retrieve Database Names. The Database Name and Username fields are automatically populated. Enter the password and click Next
7. In Advanced Setting make sure that this server will not host the Central Administration site and click Next
8.  That’s it. The new server is now member of the farm. Use Central Administration to configure it for the purpose it is intended (Web Front-end, indexing etc)