Unfortunately, aflash driveisn’t a supportedbootablemedia in this case.
As of January 2020, Microsoft is no longer supporting Windows 7.
We recommendupgrading to Windows 10orWindows 11to continue receiving security updates and technical support.

An empty CD should be large enough for a System Repair Disc.
If you only have a blank DVD or BD available, that’s okay, too, of course.
Go toStart>All Programs>Maintenance.

you’re able to also executerecdiscfrom the Run box or a Command Prompt window.
If you do that, skip directly to Step 4 below.
SelectCreate a System Repair Disc.
Choose your optical disc drive from theDrivedrop-down box.
Windows 7 will now create the System Repair Disc on the blank disc you inserted in the previous step.
No special disc-burning software is required.
SelectOKon the originalCreate a system repair discwindow that’s now on the screen.
SeeHow to Create a Windows Recovery Drivefor details.