To convert an ISO file to an IMG file using UltraISO, follow these steps:
Open UltraISO and click on the "File" menu.
Select "Open" from the menu and browse for the ISO file you want to convert.
Once the ISO file is open, click on the "File" menu again and select "Save As."
In the "Save As" window, select the "IMG" option from the "Save as type" dropdown menu.
Choose a location to save the IMG file and click "Save."
After the conversion is complete, you should be able to use Win32discimager to create a live USB flash drive from the IMG file. Keep in mind that you may need to adjust the settings in Win32discimager to read IMG files.