There may be a way to get the Windows 8.1 update if it still hasn't appeared.
Softpedia is still trolling Microsoft's forums looking for signs of Windows 8.1 issues, and has come across a number of posts regarding the update's availability. According to the site, which doesn't point to any specific post, many customers still don't see the Windows 8.1 upgrade in Windows Store even though it was released to all on October 17.
The problem actually began on day one, and was even experienced by several here at Tom's. The problem, at least initially, was that the Windows 8 platform needed to be updated with specific patches released before the update finally appeared on Windows Store. Naturally, one month later, we'd expect that Microsoft would have resolved the issue, but many users reportedly still don't have access despite fully patching their systems.
As a way around the problem, Softpedia points to this page, which provides information about updating from Windows 8.1 Preview to the full-blown Windows 8.1 RTM build. Customers are instructed to click on the "I installed the preview from the Windows Store or I installed the preview using media while Windows 8 was running" in the "Updating to Windows 8.1 or Windows RT 8.1" section, and then hit the "from the Windows Store" link in the expanded text.
The following link should actually launch the Windows Store and load up the Windows 8.1 update, regardless if customers are trying to update on a Windows RT device or a Windows 8 x86-based machine. However this "fix" will not install the update on machines running the Enterprise version of Windows 8.
Although the Windows 8.1 update is praised to be the platform's savior, its arrival hasn't come without issues for many Microsoft customers. As previously reported, some users are experiencing screen lockups; only mouse input works, and forces users to reboot the device. The update has also caused a BSOD for those trying to create a ramdisk. Gamers are also reporting mouse lag in a number of games after installing the update.