exFAT not working on xp but works on Win7 and Mac

My external drive formatted with exFAT to make is work on Mac (read & write) and Windows, just realised few weeks later it does not working on XP but works on Win7 and Mac. Yep, you need to install a Windows XP patch http://www.microsoft.com/en-us/download/details.aspx?id=19364 KB articles: KB955704 Date published: 1/26/2009 WindowsXP-KB955704-x86-ENU.exe 3.2 MB Tested and works fine (Jan 2013).