I recently came across a dmg image file that I needed to use, but the problem is that Windows does not support dmg. I tried to mount it using MagicISO, PowerISO and Alcohol %120 but none can mount the file. I found a great feature in PowerISO that lets you convert dmg to iso. Here are the steps.
1. Open the dmg file with powerISO
2. Goto Tools..Convert..
3. Select your source file
4. Select the destination file (It can be either iso, bin/cue, or daa)