You can use Magical Jelly Bean
to view your Windows product key if that is Windows already activated.Download Windows 7 Disc Images (ISO Files) from Microsoft server
using your Windows retail product key.
If you have a OEM product key then download the Windows 7 Professional ISO image from below link.Windows 7 Professional Free Download ISO 32/64-bit
You may have to uninstall Service Pack 1 as this Windows 7 ISO image does not have Service Pack 1 integrated in ISO image.
You will need to mount the Windows 7 ISO image and double click the Setup.exe
file to start repair install (in-Place Upgrade) process.
You can use WinCDEmu
to mount the Windows 7 ISO image.
Install WinCDEmu and give it permission to install the hardware driver it requires. After you do, just double-click a disc image file to mount it. You can also right-click a disc image file and click “Select drive letter & mount” in the context menu.
To unmount the disc image when you’re done, right-click the virtual disc drive and select “Eject”.
If you have any questions please let me know!