How can you kill processes and crashed applications from Windows task manager very fast?

You must make the following changes to the Windows registry.

CAUTION: We strongly recommend that you back up the registry before you make any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify only the keys that are specified. Read the document How to make a backup of the Windows registry for instructions.

Click on START > RUN and type regedit
Then click on Ok button.

The Registry Editor, will be appeared.
In the left pane of the Registry Editor, navigate to the following subkey (making double click on each registry key):

HKEY_USERS
Sid_User
ControlPanel
Desktop

Now, in the right pane of the Registry Editor locate and make double click on the following registry subkey named WaitToKillAppTimeout

If not, make it. For this case, in the right pane of the Registry Editor, right click in the white space and choose NEW > DWORD Value to create a new subkey.
Name it WaitToKillAppTimeout
Now, make double click on it.

A new window will be appeared.
Modify the value in the field named Value data (by default is 20000).
Set the value for this subkey to 5000

Then click on Ok button.

Exit the Registry Editor.

Restart the computer.