Makes an outstanding computer using industry leading parts. Compaq made one of the first competing operating systems other than MS Dos, and to this day, still has proprietary software within their components. Hence you can't maintain or update their laptops and desktops without having problems or needing their version of the same publically available software.
IBM, Toshiba, Sony and Gateway make good machines. However, and that's where you learn your mistake in purchasing their machines, their maintenance is horrid.
Dell answers the phone with live persons who have experience, keep track of previous incidents, and have credible solutions which actually solve the problems being presented. IBM was far too large even to keep track of the returned laptops which came in for service.
So, component structure of their business based on their products is what provides the sufficient strength behind DELL.
Problem is, Michael Dell continues to treat his company like a personal stock portfolio, and has had his hand slapped for trading on the company and their shares, just like a personal portfolio.