Existem dois métodos que devem funcionar para você. O primeiro método é o seguinte:
Method 1:
If you connected a second drive or any external drive to your PC (a SSD or HDD) the upgrade will fail if the second (original) drive is not disconnected. Just remove the secondary drive and all external drive, reboot and try installing the Windows 8.1 update.
O segundo método é o seguinte:
Method 2:
If you do not have any external drive connected to your PC, boot the computer in a clean boot state and then try to install and check. Booting the computer in a clean boot state uses a minimal set of drivers and start-up programs. A clean boot helps eliminate software conflicts. You can refer to this article for more information:
Para fazer uma inicialização limpa, você deve fazer o seguinte:
Swipe in from the right edge of the screen, and then tap Search. Or, if you are using a mouse, point to the lower-right corner of the screen, and then click Search.
Type msconfig in the search box, and then tap or click msconfig.
On the Services tab of the System Configuration dialog box, tap or click to select the Hide all Microsoft services check box, and then tap or click Disable all.
On the Startup tab of the System Configuration dialog box, tap or click Open Task Manager.
On the Startup tab in Task Manager, for each startup item, select the item and then click Disable.
Close Task Manager.
On the Startup tab of the System Configuration dialog box, tap or click OK, and then restart the computer.