Universal USB Installer does not recognize the iso file

Solution 1:

Try Unetbootin ,select the appropriate installer file based on your Current OS and also verify the md5sum of ISO before using it.

A suggestion , see screenshot

1. Don't select the first option Distribution , because it does not lists the current Ubuntu Precise Pangolin 12.04 edition. So rather ,
2. Select the Diskimage option , then Browse to the location of the Ubuntu ISO image from the .... button.
3. IMPORTANT option , select the Type and Drive Option Very Carefully to avoid data loss . If it is Usb Drive , most probably will be sdbX , sdcX, do a cross check and Proceed with OK option.

Solution 2:

I faced the same problem in my windows 7. It doesn't recognize not only ubuntu iso but also all other ISO I have.

I would recomend, LILI.

From here you can get it.