Microsoft said it is investing $300 million in advertising for the unveiling of its flagship MSN Internet software version 8.0.
"We are investing $300 million to communicate with people about MSN 8 because we want consumers to know that finally there is a better alternative to the status quo when it comes to internet services," Mr Yusuf Mehdi, vice president for MSN, said.
"We believe when consumers compare MSN 8 with their existing service, MSN will win, hands down, because it allows consumers to communicate better, protect their family better and browse better than ever," Mr Mehdi said.
The new MSN service will be officially launched by Microsoft chairman Mr Bill Gates in New York's Times Square on October 24th, but its campaign and ads began a day ahead of the launch of the new offering from rival AOL.
AOL is launching its new 8.0 service for US customers with a New York party tomorrow.
Both companies have tweaked their software to upgrade functions such as parental controls, instant messaging and filtering of unwanted e-mail advertising.