Hi gotpoi,
Welcome to Microsoft Community. Your interest in Windows 10 is much appreciated.
I can understand how frustrating it could be when things go unusual. I will certainly help you.
We suggest you to follow the below methods and check if it helps:
Java would work, but javac would not in the Windows command prompt (cmd.exe). For me, it was simply that I had placed a space when adding C: Program Files Java jdk1.8.0 bin to the end of my%PATH% environment variable.
Method: 1
Disable the Proxy Settings.
If this is the first time, you are trying to install Java on your Windows 10 computer, then follow these steps to disable the proxy settings.
1) Press “Windows Logo” + “R”, type “inetcpl.cpl” and press “Enter”.
2) Click the “Connections” tab, and then click “LAN settings”.
3) Uncheck the “Use a proxy server for your LAN” check box.
4) Click “Ok”.
After disabling the proxy settings, try downloading and installing Java and check if that help.
Method: 2
Temporarily disable the third party security program (If you have installed any).
If you have installed a third party security program, then I request you to contact its technical support to temporarily disable the program and then try downloading and installing Java and check the issue.
Note: Antivirus software can help protect your computer against viruses and other security threats. In most cases, you shouldn't disable your antivirus software. If you have to temporarily disable it to install other software, you should re-enable it as soon as you're done. If you're connected to the Internet or a network while your antivirus software is disabled, your computer is vulnerable to attacks.
If you are using the online Java installer, then I would suggest you to try the offline installer package and check if that works. Often the offline package will install successfully while the online installer package encounters a problem.
Method: 3
Download Java For Windows 7
Try Offline Installation of Java.
Install Java Windows 10 Pro
I would suggest you to download the offline installer package from the given link and then install it successfully. The link for downloading the Java Offline installer package is:
Install Javac Windows 10 Windows 7
For more information, you may also refer the article: “Download and Installing Java” from this link:
As a reference, you may also check this link for other download errors with Java:
Keep us posted if you face any issues on windows in future. We will be glad to help you.