Activating Windows 8.1 using Microsoft Toolkit 2.5.3

I recently began experiencing a problem with my computer in that a pop-up keeps appearing telling me that I need to activate windows by the 26th June (2015). I am presuming that if I don't it will shut down. Anyway, I did some research and spoke to a friend and came upon the microsoft toolkit 2.5.3 which seemed like the perfect solution to my problem. I downloaded the toolkit, tuned off all anti-virus software, ran it as administrator, opened the "Activation" tab and clicked on EZ-Activator just like the instructions on all of the sites I visited indicated to do, but all that happened is that a text message that read "Invalid Class" appeared (Green text in the black box)......Does Anyone Know What This Means And How I Can Overcome The Problem.

Thanks in advance

Kurt

Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows 8.1, 64 bit
Processor: Intel(R) Xeon(R) CPU E3-1270 v3 @ 3.50GHz, Intel64 Family 6 Model 60 Stepping 3
Processor Count: 8
RAM: 32702 Mb
Graphics Card: NVIDIA GeForce GTX 760, -2048 Mb
Hard Drives: C: Total - 114469 MB, Free - 9190 MB; D: Total - 1907708 MB, Free - 124525 MB;
Motherboard: ASUSTeK COMPUTER INC., Z87-WS
Antivirus: Norton Internet Security, Updated and Enabled