You do not necessarily need a "Lenovo-specific" ISO. A standard, retail Windows 7 Professional ISO (from Microsoft) will work with a Lenovo computer, provided you have the correct activation method.
In the past, Microsoft hosted direct download links for Windows 7 ISOs. However, those links were discontinued several years ago. This leads users to search for specific ISOs labeled "Lenovo OA." windows 7 pro oa lenovo iso download
As he booted up the laptop, Alex was greeted by the familiar Windows 7 login screen. However, his excitement quickly turned into frustration when he realized that the laptop was still running on a trial version that would expire soon. He needed a full version to continue his work without interruptions. You do not necessarily need a "Lenovo-specific" ISO