How to Create Windows 7 Bootable DVD using Nero

You should be able to write to a .nrg or .iso file through Nero's image burner. I am currently using Nero 10 but it should be the same exact process in 9 IIRC.

To make an ISO of a disc*:

1. Select the Image Recorder as your recording device.
2. Start the disc copier.
3. Configure your settings.
4. When it asks for the image location, change the save type to ISO Image File.
5. Save.

To make an ISO of your project:

1. Start your project and add the files you want on the image.
2. Select the Image Recorder as your recording device.
3. Burn it.
4. Verify the settings.
5. When it asks for the image location, change the save type to ISO Image File.
6. Save.

Note: If it is a protected disc, burning may not work due to the protection mechanisms. You'd need some software to bypass the protections in order to do so and have it work. Free software such as Alcohol 52% can make these images for you (and provides a virtual drive to mount these images to) or paid software such as AnyDVD (HD) can bypass and record.

I totally agree with you, downloading ISO from Microsoft and using a USB drive is a nice idea. And USB works really quickly as compared to DVDs. But what if the user wants to create bootable iso for Windows 7. In that case, you cannot download the iso from the Microsoft official website without the genuine product key.

And in that case, creating an ISO from Windows installation files would be a better option.

And Yes it depends on the user to user.

So if you want to create bootable iso from folder or files follow this guide:

1. Install ImgBurn tool
2. Click on create an image from files/folder
3. Now Select the folder directory
4. Now Make ISO image bootable
5. Configure advanced bootable settings

For more info, you can also follow the original source link.

That's it. By using these steps you can easily create an iso file & use it in USB.

Thanks.