Hi. I've removed my hard drive from my laptop which had windows 8.1 os on it to put it on a desktop which also has windows 8.1 to run alongside the desktop hdd to copy files from the desktop hdd. Upon replacing the hdd to my laptop,I noticed my desktop background was black,all my tiles was missing on my start screen and couldn't access file explorer or nothing on my laptop. How do I fix this?

How to  refresh, reset, or restore your PC

Hello Marcmillion,

What is your current situation?

Do you mean that you connect the laptop HDD to the desktop to copy file

As you have black screen and Windows Explorer issue, please refer to the following article to fix this issue.
http://windows.microsoft.com/en-HK/windows7/why-is-my-screen-black-when-i-start-windows-7
This article is about Windows 7, and Windows 8.1 is similar.

Check if you can normally boot in the safe mode, if you can, please try to update the drivers.

Best regards,
Fangzhou CHEN