1
Before using the ISO, please try these steps for the webcam problem.
Look at the function keys (F1 - F12) on your keyboard, if one of them has a camera icon, press that key or Fn + that key to unlock the webcam.
If that was not the problem, look at the camera lens above your screen, is there a small privacy slider that needs to be opened to access the webcam?
If the webcam is still not working, go to the support page for your laptop on the manufacturers website, then from there, download and re-install the version of webcam drivers they provide.
2
If the webcam is still not working, if you have the ISO downloaded, you do not need a DVD or USB, you can use these steps to perform an in-place repair with the ISO.
Disconnect from the Internet
Disconnect all external devices with the exception of a mouse or keyboard.
Temporarily disable any 3rd party Anti-virus you may have installed
Then, in Windows File Explorer, double click the ISO and then run Setup.exe and select the Install option.
At the start of the process, you will be asked if you want to download other updates, select No.
Very Important - ensure you select the option to keep your files and apps.