Microsoft is playing a new card to get its Windows XP users to upgrade to later versions of Windows desktop OS with a $100 discount on PCs worth more than $599.

Microsoft is pushing hard on Windows XP users to upgrade before the software giant stops supporting the 13-year-old OS. After series of warnings and posts addressing the security risks involved with the continued usage of Windows XP after its end-date on April 8, Microsoft is giving a discount offer exclusively for Windows XP users. The Redmond software giant is offering a $100 discount on purchasing machines worth more than $599.

The discount covers a wide range of computers, including the Surface Pro 2, provided they are bought at a Microsoft store. The offer kicked off Thursday and will run through June 15 or while supplies last. Microsoft highlights two options for users, the HP ENVY TouchSmart 15 touch screen laptop and Lenovo's 2-in-1 ThinkPad S1 Yoga tablet-laptop hybrid.

To avail the discount, XP users must present the device running the 13-year-old desktop OS at the store. With one XP-running machine, buyers can only avail the $100 discount once.

Microsoft has repeatedly reminded users to upgrade their desktop OS from Windows XP to higher versions. The company was persistent with its advice to make consumers jump to Windows 8. Several users criticized Microsoft for what appeared to be more of a sales pitch. But, if Windows XP users choose to continue using the OS, they have two options. Customers will have to  pay $200 for first year, $400 for second and $800 for the third year simply to get technical assistance from Microsoft. But if customers choose not to take that and continue using XP without upgrading, then Microsoft warns their computers will be at high risk of cyber attacks.

If customers are serious about the data stored on their XP machines, then there are plenty low-end Windows 8 computers and some Windows 7 machines, too. Without customers' consent, Microsoft will not be able to push 29.53 percent XP users to upgrade. According to Net Applications, Windows 7 is the most dominant OS in the market with 47.31 percent market share and Windows 8 and 8.1 accounts for 10.68 percent.

With less than three weeks in hand, Microsoft will face a significant amount of pressure in shifting the massive audience from XP to higher Windows operating systems.