Initialpage123.com is a search engine that can be set as your browser's new tab, default search engine, or homepage through the use of browser hijackers. It's highly annoying because it displays additional ads and sponsored results on top of normal search results, often leading to poor quality or irrelevant pages that don't help you at all. Fortunately, there are several ways you can remove it from your PC and browsers once and for all.
Typically, this search page is brought to your attention because you accidentally agreed to install a browser hijacker or Potentially Unwanted Program (PUP.) These apps are not harmful, but they may often cause unwanted side effects and changes to your browser's behavior – such as replacing your default new tab page or search engine. Often, such apps might be installed through software bundles, fake downloads, or deceptive ads – be careful with the software you choose to download and install.
If Initialpage123.com keeps returning to your browser settings even after you remove it manually, you will need to run a PC security utility to get rid of the PUP/hijacker forcing this change.