Google is gunning after Microsoft Corp.’s Internet Explorer. On Monday the search-engine giant launched its own Web browser, called Chrome.  Google said the software is designed to make it faster to browse the Internet and easier to run applications without dowloading software to a computer. The product is open source, allowing others to modify the code. Meanwhile, Google CEO Eric Schmidt last week told Bloomberg Television that Yahoo and Google’s paid search deal is officially on. Schmidt said Google would probably start serving some of the sponsored listings on Yahoo’s search pages by early October.