Thank you for all the comments...I haven't been around for a while, but was pleased to find some replies to my query.
My first computer was from Tiny, and I was a complete newby, having no idea about discs, but then I purchased another from Curry's (Compaq)...no OS disc, and then I got my laptop (Toshiba) from PC World...again no OS disc.
As you say, I should have asked the right questions before my purchases. But, you live and learn
The penny drops eventually!