Originally Posted by TeddieLN
how to uninstall Linux UBUNTU without boot CD?
you don't simply uninstall an operating system (OS) like you uninstall a spreadsheet application or a chess game that you don't like any longer. The operating system is the core software component on a computer. If you remove or "uninstall" it, you end up with an unusable computer.
So I guess you're not simply planning to uninstall Ubuntu, but rather, to replace it with a different OS. The usual procedure is to boot the alternate OS from its installation media (CD, DVD, bootable USB drive) and start its installation procedure. In the process of installing that other OS, you'll simply delete the partitions that once had Ubuntu on them, and re-create partitions for the new OS.
There's a situation which is particularly easy: If you had a dual-boot configuration with another OS beside Ubuntu, you can simply boot that other OS and use its partitioning tool to delete the Ubuntu partition, thus gaining space to use for your alternate OS.
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