First reinstall Opera and Chrome, second do a virus scan (I recommend Malwarebytes Anti-Malware Free) just to make sure that there is no virus on computer, third reinstall your antivirus software (if you have).
If steps above doesn't help try to clean boot Windows.
Here is tutorial for clean boot.
If you can't download either in clean boot try to boot Windows in Safe Mode with Networking
Here is tutorial how to boot into safe mode.
If you can download files in clean boot there is probably some software that is blocking downloads.
Install AdwCleaner and run a scan. Also I recommend you to look for some suspicious software. You can do that by installing Revo Uninstaller. On the list of programs look for programs that look suspicious. Remove them with Revo Uninstaller.
Edited by HrcaA3000, 31 October 2016 - 03:55 PM.