Microsoft has a problem: It desperately wants any remaining Windows XP users to upgrade to a newer version of the operating system but a huge chunk of them still haven’t budged. The latest numbers from NetMarketShare show that Windows XP still accounts for around 29.5% of all desktops in use even though Microsoft is due to end support for the 13-year-old platform on April 8th. ZDNet reports that Microsoft plans to pester remaining XP holdovers starting next week by sending them pop-up notifications reminding them — again — that it will end XP support within a month. However, as Computerworld reports, Microsoft may have a tough time convincing some Windows XP users to upgrade because it’s trying to sell them