Final answer:
The unwanted software pre-installed on a new computer that can slow it down is called a Potentially Unwanted Program (PUP). PUPs are not usually malicious but can be intrusive and affect system performance. Removing these programs can help improve the computer's speed and efficiency.
Step-by-step explanation:
The type of software that comes pre-installed on a new computer that the user doesn't want and may slow down the computer is known as PUP, or Potentially Unwanted Program. Pre-installed software, also sometimes called bloatware or crudware, often includes various trial versions, utility programs, and promotional software that many users find unnecessary and intrusive. These programs can consume system resources and affect the computer's performance negatively. Unlike spyware or keyloggers, PUPs are not generally malicious or illegal, but they can be annoying and may lead to cluttered system space, causing slowdowns. It's recommended that users go through their installed programs and uninstall any unwanted software to improve their computer's performance.