Ubisoft has announced that its Uplay PC client is set to end support for Microsoft's Windows Vista operating system. Posted on its help site, Ubisoft says that the reason for ending support is due to Windows Vista becoming end of life soon:
With official support for Windows Vista soon to end, we have decided to end our support of this now legacy operating system. This will allow us to take advantage of newer technologies moving forward and ensure the highest possible security for our users.
For those who are still using Windows Vista, games will continue to be playable, however, future Uplay PC client updates will not be installed, potentially leaving open any security holes that currently exist, as well as any bugs.
It is recommended to upgrade to a newer version of Windows, such as Windows 10, to continue to receive Uplay updates.