Quit Disk Utility and install El Capitan. If you already attached the SSD you can use Internet Recovery Mode (hold cmd R or alt cmd R while booting) to first partition the new internal drive and then restore the original system (10.7 Lion). Then - after configuring Lion - you can to upgrade to El Capitan. Before you can use your new SSD with your Mac® system, or install macOS® onto it, you have to initialize and partition it first. Follow the steps in this article if you are using OS X El Capitan or later. If you have not upgraded, follow our guide for earlier versions of OS X.

How To Install El Capitan On New Ssd Hard Drive
El Capitan Reinstall

I have a Macbook Pro Medio 2012, 15 Inch Non Retina.
It was running on a normal 750G HDD, but i wanted an upgrade, so i bought the Samsung V-Nand 850 EVO SSD 1TB.

I created a Bootable El-Capitan USB Stick, so i could do a clean install.
After i swapped the HDD with the Samsung SSD, i plugged in my Bootable USB stick and turned on my macbook.

First it shows the apple logo with a loading line.
after that i gives me a 'stop sign'. A circle with a line running through it.

I also tried pressing the Command button while it starts up, but that didn't work.

I'm trying to clean install El Capitan on my Macbook pro. Slugterra games.

Does anyone know what to do?

Kind regards in advance!

To get the latest features and maintain the security, stability, compatibility, and performance of your Mac, it's important to keep your software up to date. Apple recommends that you always use the latest macOS that is compatible with your Mac.

Learn how to upgrade to macOS Big Sur, the latest version of macOS.

How To Install El Capitan On New Ssd Hard Drive

Check compatibility

The version of macOS that came with your Mac is the earliest version it can use. For example, if your Mac came with macOS Big Sur, it will not accept installation of macOS Catalina or earlier.

If a macOS can't be used on your Mac, the App Store or installer will let you know. For example, it might say that it's not compatible with this device or is too old to be opened on this version of macOS. To confirm compatibility before downloading, check the minimum hardware requirements:

El Capitan Reinstall

macOS Catalina 10.15 hardware requirements
macOS Mojave 10.14 hardware requirements
macOS High Sierra 10.13 hardware requirements
macOS Sierra 10.12 hardware requirements
OS X El Capitan 10.11 hardware requirements
OS X Yosemite 10.10 hardware requirements

Download macOS using Safari on your Mac

Safari uses these links to find the old installers in the App Store. After downloading from the App Store, the installer opens automatically.

macOS Catalina 10.15 can upgrade Mojave, High Sierra, Sierra, El Capitan, Yosemite, Mavericks
macOS Mojave 10.14 can upgrade High Sierra, Sierra, El Capitan, Yosemite, Mavericks, Mountain Lion
macOS High Sierra 10.13 can upgrade Sierra, El Capitan, Yosemite, Mavericks, Mountain Lion

Safari downloads the following older installers as a disk image named InstallOS.dmg or InstallMacOSX.dmg. Open the disk image, then open the .pkg installer inside the disk image. It installs an app named Install [Version Name]. Open that app from your Applications folder to begin installing the operating system.

macOS Sierra 10.12 can upgrade El Capitan, Yosemite, Mavericks, Mountain Lion, or Lion
OS X El Capitan 10.11 can upgrade Yosemite, Mavericks, Mountain Lion, Lion, or Snow Leopard
OS X Yosemite 10.10can upgrade Mavericks, Mountain Lion, Lion, or Snow Leopard