Attached Link: http://filext.com/file-extension/DMG

Correct, .dmg files are disk images that can only be mounted on a Mac. They can't be used on a Windows PC without additional third-party software.

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)