DMGExtractor!

CD image files are easily created with UltraISO. Duplicate discs to a CD image, create bootable CDs and audio CD images - and UltraISO also handles DVD image files. If you need to know how to make a CD image or need to edit an ISO image file, UltraISO is the tool you need.

[Lite version is totally free but it cannot deal with files greater than a regular CD size (870 MB) ].

TransMac Details (open Mac disks and dmg files on a Windows PC). Open Macintosh format disk drives, flash drives, CD/DVD/Blu-ray media, high density diskettes, dmg and sparseimage files. Runs under Windows 7, Vista, XP, 2000, Server 2008 and 2003.

dmg2img is a free command-line utility that converts a compressed dmg file [MAC] to a standard image disk [WIN].

DMG Extractor is a Windows DMG opener for Mac OS X DMG Disk Image files.