When Microsoft stops supporting and upgrading Windows XP on April 8, any remaining Microsoft Dynamics customers with users running legacy XP systems will want to have a plan to get those systems upgraded or isolated.
Namely, migrate all your remaining computers off XP or - if you're running other legacy hardware or software that requires XP - make sure the old PCs are well firewalled off or, ideally, disconnected from your company network and the Internet altogether. Otherwise, without Microsoft system updates and security...