Sony might not be making PCs anymore, but it's still on the hook for supporting its older systems -- and that's creating a big problem for Windows 10 upgrades. The electronics giant is warning owners against installing Microsoft's latest software on older VAIO PCs until it has the drivers needed to get all the hardware working properly. And unfortunately, that's going to take a while. If your computer first ran Windows 8.1, the Windows 10 drivers won't be ready until October; if it's old enough to have shipped with Windows 8, you'll have to wait until November.