Hello Anclara,
Thank you for your response.
As you have tried all the troubleshooting to resolve this issue, I would suggest you to perform in-place upgradeand check if it helps. Please follow these steps:
a. Insert Windows 8.1 installation disk(DVD) in the DVD drive.
b. Press Windows + X keys and select file explorer.
c. Right click the DVD and select "Open".
d. Double click "Sources" folder to open it.
e. Scroll down to find "setup" and double click "setup".
f. Click "Install Now" and follow on-screen instructions.
g. Select "Upgrade" when "Type of installation" window appears.
Windows may check for compatibility and then in-place upgrade starts. Windows may restart several times while performing in-place upgrade.
If you do not have Windows 8.1 disk, please refer to this link to download it. Windows 8.1 key is required.
http://windows.microsoft.com/en-US/windows-8/upgrade-product-key-only?woldogcb=0
Note: I highly recommend backing up all of your important files and folders onto an external storage device before attempting any type of operating system repair or upgrade.
I hope this information helps.
Thank you