Europeans got their money back
Step into the TARDIS and revisit the era this decision came from. Last millennium phones were for talking to people and they had physical buttons with numbers on for sending text messages. Apple had a small niche market and Linux was less famous than the BSD Unixes are today. If a techy searched really hard, he could buy a desktop PC with freedos, but everyone else (and anyone buying a laptop) had to buy Windows. By itself, having a monopoly is not illegal. Using a monopoly in one field (ie Operating systems) to gain a monopoly in another (like web browsers) is illegal.
The wheels of justice grind at the speed of a doped two legged donkey. By the time the EU even noticed, Netscape Navigator as a commercial product was already dying. The actual complaints were about media streaming and network file systems. People were using cheap ARM CPUs and SAMBA for NAS instead of power hog Intel CPUs and and expensive NT server licenses. Microsoft fiddled with the protocol to break SAMBA and require people to use Windows. After years of delaying tactics from Microsoft, the EU fined Microsoft €497 million and ordered them to document the SMB protocol (now called CIFS). Again Microsoft took their time, and were fined an addition €1.5 million per day for 187 days before they made the documentation available for purchase (the fine was about to go up to €3 million per day).
That €777 + 80% of the EU's legal expanses were tax revenue that Europeans did not have to pay. It would be nice to claim that Europeans made of profit on the deal, but clearly breaking the law was benefiting Microsoft (and costing Europeans) between 1.5 and 3 million Euros per day.
SAMBA was not made using Microsoft's documentation, which apart from being years later and expensive, was incomplete and inaccurate. SAMBA was in fact made by bugging the network connection between and Windows sever and client, guessing what the packets meant and trying them out to see what the server or client did in response (the result was more reliable than Windows - perhaps because SAMBA devs did not rely on defective docuementation). It would be nice to say that your NAS does not require a €599 Windows server license because of the EU court order, but that would be stretching the truth. Windows licenses prices are kept below €999 per CPU core because Microsoft has to compete with Linux (if they didn't, home users would still be using a descendent of ME). The European Court of Justice are certainly too little and far to late, but they do pay for themselves many times over.