If you have an old product key (even from a dead computer’s COA sticker), you can download the official Windows 7 SP1 ISO from Microsoft (still available via the Software Download tool for valid keys).
: Indicates that the installer contains six different editions of Windows 7 within a single file. Users can typically choose between versions like: Home Basic Home Premium Professional Enterprise. WINDOWS 7 SP1 X86 MULTILANG.6X1 PRE ACTIV-EN-AR...