Going back to absolute basics here. The answers on this page and a little googling have brought me to the following resolution to my issue. Steps to restart the apache service with Xampp installed:-

1. Click the start button and type CMD (if on Windows Vista or later and Apache is installed as a service make sure this is an elevated command prompt)
2. In the command window that appears type cd C:\xampp\apache\bin (the default installation path for Xampp)
3. Then type httpd -k restart

I hope that this is of use to others just starting out with running a local Apache server.

I have used the Apache Lounge distribution indicated in the official Apache 2 documentation (https://httpd.apache.org/docs/2.4/platform/windows.html)

These are the steps to install Apache on Windows using Apache Lounge distribution:

1. Download Apache 2.4.37 Win64 (https://www.apachelounge.com/download/)
2. Create folder C:/Apache24
3. Unzip httpd-2.4.37-win64-VC15.zip in folder C:/Apache24

Option 1: To run it from the console:

4. Open Windows Power Shell

5. Execute httpd.exe

   PS > C:\Apache24\bin\httpd.exe
   

   or

   PS > cd C:\Apache24\bin
   PS > .\install.exe
   

6. Open http:\localhost or http:\127.0.0.1 in brwoser

The message It works! will be displayed

Option 2: To install it as a service:

4. Open Windows Power Shell

5. Open Windows Power Shell as administrator

   PS > Start-Process PowerShell -Verb RunAs
   

6. Install the service

   PS > cd C:\Apache24\bin
   PS > .\httpd.exe -k install
   

7. Start the service

   PS > .\httpd.exe -k start
   

   or through the services administrator

   PS > services.msc
   Select Apache2.4 > Right-click > Start
   

8. Open http:\localhost or http:\127.0.0.1 in brwoser

The message It works! will be displayed