How To Recover Windows 8/8.1 Product Key From BIOS/UEFI:

Step 1: Head over to this page and download Windows 9 Product Key Viewer.

Step 2: Run the program and check the option labelled MSDM key to view your genuine program key.

And if Windows 8/8.1 wasn’t bundled with your PC and you manually installed it later, you can view the product key by unchecking MSDM Key box. 

Enable Task Manager disabled by Administrator or Virus in Windows

Windows Task Manager is used to view details about processes running on your computer. Since it can be used to terminate programs that are misbehaving or are viruses disguised in the form of harmless programs, most spyware and viruses disable it to prevent themselves from being closed through it. Some administrators also disable Task Manager to prevent users from closing important security programs like antiviruses and anti-malwares.

In such situations, running the Task Manager will give the "Task Manager has been disabled by Administrator" error. However, there are some techniques you can use to re-enable task manager and close those harmful programs manually. This article contains few such simple techniques you can use to regain access to Task Managing privileges.

Enable Task Manager from Registry in Windows 8, 7, XP or Vista

Registry Editor is an inbuilt Windows tool that is used to modify registry keys which tell Windows how it should work. A simple registry modification can be used to bypass the Task Manager block. To do so, just follow the steps:-

1. Click on Start. Go to Run. If you use Windows 8, Windows 7 or Windows Vista, go to Search.
2. Type regedit and press Enter. Registry Editor will start. 
3. Through the left hand navigation pane, navigate to HKEY_CURRENT_USER\Software\Microsoft\ Windows\ Current Version\Policies\System. If the System key is not there, you will need to create it.
4. In the work area, locate "DisableTaskMgr". If this value is not there, you will need to create a new DWORD value called DisableTaskMgr. Double click on it. A window will pop up.
5. Enter its value data as 0 and press OK.
6. Close Registry Editor. If Task Manager is still disabled, restart your computer.