If you need a license for Mathematica, please reach out to the ServiceDesk for assistance (firstname.lastname@example.org).
Once your licensed is provisioned for you, you will receive an email with your license key and a link to create a Mathematica account. If you don't want to, you don't have to create a Mathematica account.
This email will come from "Wolfram Customer Support", if you need to search for it in your email inbox.
On a Mac, download this package.
On a PC, download this package.
Once downloaded, click on the package to open it up. Double click on the "Download Manager for Wolfram..."
Click next when asked where the downloader should place the downloaded file.
Then, you'll see a progress bar for the download.
After the download has completed, the installer will kick off. Walk through the steps of the installer by clicking "Continue" and "Install" until the product starts to install on your computer.
Once installed, the product may launch. If it doesn't, launch the application. On a Mac, you can find Mathematica by using Spotlight search, and on Windows you can search using the start menu.
After Mathematica has launched, you'll be brought to a screen to license the software.
Click on "Other ways to activate".
Select "Online Activation (Recommended)". Enter the license code from your email (you can copy/paste).
After you click the "Activate" button, the program will give you a spinning graphic for a few seconds, and then tell you that you're activated.
Approve the license agreement, then you'll be all set.
Signing up for a Wolfram Account
In the email you were sent, click the Link below "To download your product from the Wolfram User Portal..."
Clicking this link will bring you to Wolfram's site to sign-in or create a new account. Click "Create one".
Be sure to use your SNC email address when creating the account. Once you've entered your information, click "Create Wolfram ID".
This will send you an email asking you to confirm your email address. Click on the link in that email to confirm.
Once logged in, and after you've confirmed your address, you'll be able to see the products available to you. You'll also be able to download the packages I linked in the top section, if you'd like to perform the entire download/install procedure by yourself.