Blank purple login screen on windows 8

Hi Mollee,

Thank you for posting your query in Microsoft Community.

I understand that you are getting blank purple screen at log-in screen. I will be happy to assist you with your query. Let me ask you;

1. What is the make and model of the computer?
2. Did you recently upgrade to Windows 8.1 from Windows 8 through Microsoft Store?
3. Which operating system was installed when you bought the computer?
4. Do you have installation media for Windows 8.1?
5. Did you make any specific change in the computer prior to the issue?

This issue might occur if some other service or application is running at the startup and is taking time to initiate the startup period. This can also be caused due to some third party program causing the issue, due to display adapter drivers or corrupted/missing system files. Let's try the methods below and check.

Method 1: While you are at blank purple screen, press Ctrl + Alt + Delete and check if you get any option to sign-out or taskbar.

If you get any option to sign-out, sign-out and sign back in and check.

If you get option to go to task manager, check if any program is still running and causing the error.

Method 2: Perform automatic repair using Windows 8.1 installation media

Note: If Windows 8.1 was pre-installed at the time you purchased it, you can contact the computer manufacturer for the media.

Please try the steps below to run automatic repair.

a) Insert the installation media and boot Windows 8.1 from it.

b) In the ‘Windows setup’ page select the ‘Language to install’, ‘Time and currency format’ and the ‘keyboard or input method’ and click on ‘Next’.

c) Click on ‘Repair your computer’ and select ‘Troubleshoot’.

d) Click on ‘Advanced options’ and select ‘Automatic Repair’ and follow the instructions.

As of now, please try the methods above and keep us posted, we'll be happy to assist you further.