OS Support Policy

I recently attempted to upgrade BO client tools from BI4.0 to BI4.1 on two workstations, one running Windows XP and another Windows 7 (no SP). On both machines, I was unable to do so, as the installer would not let me continue past its failed prerequisites check.

This concerns me. It's one thing for us to make a conscious decision to run software in an unsupported configuration, knowing that we may not get support from SAP if we run into a problem. But it's another thing to be prevented from doing so. Especially considering that Win XP is still in extended support.

As with most medium to large businesses, our BI team has little say in the version of OS that is installed on our workstations and servers. I'm concerned that we might find ourselves in a situation in which we are unable to install a necessary BO patch or upgrade, because we are not on the latest OS.

So, my question is, what is SAP's policy with regard to OS support? Why is SAP not supporting an OS that is still in extended support, and still used on a third of all desktops? (according to http://www.netmarketshare.com/)