When we insert a blank DVD into the DVD reader in Windows 7 it will ask whether to use it as an USB or as a normal DVD. When I select to use it as an USB, it will format the DVD and allows me to use it as an USB. My question whether this process is reversible, that is can I use the DVD as a normal one by burning data into it after formatting to make it work like a USB. When I tried to burn anything into the disk using NERO after formatting, it was showing an error.
No, when it ask whether you want to use it as USB, it just mean that you can drag and drop files to the DVD and the files will be put onto the DVD without you having to burn it. It won't make the DVD into a USB (not rewritable when using DVD-+R).