The company has replaced its windows live messaging service with Skype's after acquiring the company in 2010.
Microsoft is planning to replace Windows Live Messenger (WLM) with Skype's messaging tool over the next few months.
In October 2011, Microsoft had acquired Internet voice and video communication provider Skype for $8.5bn.
"Skype and Messenger are coming together, millions of Messenger users will be able to reach their Messenger friends on Skype, said Skype in a blog post." By updating to Skype, Messenger users can instant message and video call their Messenger friends.
The company will stop Windows messenger worlwide (exept mainland China) by the first quarter of 2013.
"We want to focus our efforts on making things simpler for our users while continuously improving the overall experience," said Tony Bates, Skype division president."We will work with you over the next few months to help you transition and offer information and help along the way."
WLM was launched in July 1999 when it was known as MSN Messenger and had 330 million active users in 2009 but recently the number has decreased to about 100 million.
In August this year, Skype had updated its iOS app with new photo sharing feature, enabling users to take a photo from their gallery or take a new snap and send them to their friends and family over Skype with their iPhone and iPad.
In February this year, Microsoft had revealed that a beta version of Skype will be available for all Windows Phone 7 customers.