I have purchase a Reseller web hosting account from cpwebhosting.net and start my own web hosting company. Is there a way to remove “H-Sphere” name from the title bar and replace it with my own company name?

To remove “H-Sphere” name from the title bar do the following:-

1) Under root, login as cpanel superuser:
# su – cpanel
To implement customization correctly, all template files and directories should have cpanel:cpanel ownership, and the make directive (see no. 7 below) should be run ONLY under the cpanel user.
2) Copy the top.html.in template from ~cpanel/shiva/shiva-templates/common/design/ directory to the custom template location (e.g.: ~cpanel/shiva/custom/templates/common/design/).
3) In the <title> tag, replace “H-Sphere” with the name you need. You can also replace it with the company name variable used in the system: ${settings.name}
4) If necessary, repeat steps 1 and 2 for other design locations (e.g. nomenu and textbased).
5) Open file ~cpanel/shiva/psoft_config/hsphere.properties and check the USER_TEMPLATE_PATH variable. It must be uncommented and contain the correct location for your custom templates.
6) Change directory to shiva-templates/ and run ./configure
7) Run make
If the changes haven’t taken effect, restart H-Sphere.
More on Template Customization.