Just follow the steps one by one :
1. Assume that your new port number is 8453
2. Go to C:\Program Files\Apache Software Foundation\Apache2.2\conf and open the file httpd.conf
3. Find this line- Listen 80
4. Replace with the following line – Listen 8453
5. Save the edited file
6. Goto C:\Program Files\Apache Software Foundation\Apache2.2\bin and run the file httpd.exe to restart the server.
Yahoo!! its done.
