It depends on what browser you are using:
If you are using Internet Explorer, click on tools (in the upper portion of your screen), then click Internet options. In the homepage section, type the address you want to use as your homepage, then click "OK". Then click "Ok" and you are done.
If you are using Netscape Navigator, Using the Netscape Edit menu, go to Preferences. Within Preferences, select the Navigator category. In the Navigator Starts With section, choose Home Page. Type whatever address you want to use as your homepage in the Home Page Location box, and click on OK.
Vroom Search Page becomes part of your search engine because YOU either:
Clicked the 'make start page' link on the main Vroom Search Page webpage.
Or, you downloaded and installed one of their MANY software applications. In the terms and conditions of any of their software products it is clearly stated that they grant you a free license to use the software and by installing the software on your computer you agree to use thier search services in your web browser. Any and all changes made to your system are clearly stated in the terms and conditions and are fully un-installable via a separate uninstall program whic you can usually find on their homepage if yah look closely.