High internet data usage. I have Windows 11 & have very high data usage through the system.

High data usage on Windows 11 can stem from various factors, including background updates, cloud services, or malware. To manage this, consider the following steps:

1. Set a Metered Connection: This limits background data usage. Go to Settings > Network & Internet > Wi-Fi/Ethernet and toggle on Metered connection.
2. Set Data Limits: Navigate to Settings > Network & Internet > Advanced Network Settings > Data Usage. Here, you can enter a data limit for your connection.
3. Check for Malware: Run a security scan to ensure no malicious software is consuming data unnecessarily

Its Delivery Optimization is a Windows 10 feature that allows your computer to download updates, apps, and other content from both Microsoft servers and other PCs on the internet. This helps reduce the load on Microsoft's servers and can potentially speed up downloads for you and others on your network.However, Delivery Optimization can also consume a lot of bandwidth, especially if you have a slow internet connection. Many users have reported issues with Delivery Optimization using up all their bandwidth.

Disabling Delivery Optimization is generally safe and can help free up bandwidth if it's causing issues on your system. You already did by modifying registry value.

Yes, the Windows Firewall can contribute to high data usage.