Install error: Specified nonexisting disk sda in clearpart command
During instalation you get the error below.
This is noramly casued by the harddisk configuration. Some bios ships with a fake-raid setup that require one to load a proprietary driver during the installation. Fake-raid is generelt bad, and should normally only be used for PC's where you want to dual boot Linux and Windows. The best is just to disable this function all together. Reboot and enter the bios, then set SATA mode selection to "Native Mode".
Where in the bios this option is located may very from manufacturer to manufacturer. For HP it is lokated at Advanced -> Harddisk Configuration.