In 1987, a beginning computer user was overheard saying in a new York store that he was having trouble learning Microsoft DOS, the new disc operating system for personal computers.

1987年，有人听到一位电脑初学者在纽约一家商店中说他在学习微软的DOS系统(适用于个人电脑的一种新的磁盘操作系统)时感到有困难。

youdao

Chances, are, however, you keep a backup copy of your operating system on an optical disc in the desk drawer, just in case.

FORBES: Apple Just Killed The Optical Drive

And the release of Microsoft's Windows 8, an operating system that works on disc-free smartphones and tablets as well as laptops and PCs, suggests that computing giant would be well positioned for such a move as well.

CNN: Why disc drives are an endangered species

It takes the software packages developed by Linux volunteers, tests them, assembles them into a working operating system and ships the result on a compact disc along with a manual and a promise of support.

ECONOMIST: Free software