As of May 2026, Microsoft has long ended official support, but verified methods still exist to obtain these files securely.
(from MSDN original):
Open Rufus, select your USB drive, and then click "Select" to locate your Windows 7 Pro ISO.
Windows 7 is no longer receiving security patches. Using it on an internet-connected PC is highly risky.
To download and install Windows 7 Pro from an ISO file:
For those with Dell hardware, the Dell Support site provides a recovery tool that can download an official Windows 7 Pro ISO using your service tag.