Removing Delta Search Engine From Mozilla

To complete  removing  Delta Search engine and Delta Tool bar from your Mozilla Firefox browser :

For removing Delta search engine

• Open Mozilla Firefox browser
• Go to search column at the right top of the browser, see the small magnifier, click on it then choose Manage Search Engines

• Select My Online Search, then click Remove

To Remove Delta Startup Page / Home page

• Go to Mozilla Firefox options
• Click Firefox >> click Options >> click Options,

• Choose General tab, then change/set the home page from Delta to other that you want.
• Click Ok to save the configuration

To Remove Delta  from  default search engine

• On the address bar type: about:config
• Then will appear notification/warning "This might void your warranty!", click the  I'll be careful, I promise!

• Type delta on the filter column, then press Enter
The result will appear and displaying the  two preference names with the value begin with,
• Right click on the first value, then click Reset 
• Right click on the second value, then click Reset

Removing Delta Toolbar
• Open  Mozilla Firefox
• Go to Firefox Option, and choose Add-ons
• Remove/uninstall  Delta extension


Good Luck.