[header] How to install ubuntu linux without cd (windows ) [title] Check your available space. [step] You'll need at least 7 gb of free space on your computer to install ubuntu, but you'll want more if you intend to install programs or download lots of files. You'll be able to install ubuntu alongside windows or replace windows entirely. 
[substeps] If you're planning on replacing your windows installation, make sure that all of your important files are backed up. Ubuntu will erase the drive containing windows if you choose to replace it.