You can download the Debian ISO file from the official Debian website at the following URL:
It would be best to use a download manager when downloading large or multiple files at once, as it can help make the downloading process more efficient and reliable. Additionally, suppose you have a slower internet connection or experience frequent interruptions while downloading. In that case, a download manager can help improve your download speed and stability.
You may need to enable VMX (Virtual Machine Extensions). Check your PC firmware configuration manual on how to do this. E.g.,
You may need to disable Hyper-V on Microsoft Windows to install VirtualBox. You can do this by running the following command in Admin PowerShell:
dism.exe /Online /Disable-Feature:Microsoft-Hyper-V