I got an error while using Windows 7 Lenovo laptop saying 'this copy of windows is not genuine'?

I have Build 7601

I've been trying to find an answer online and one website said you need to:

1. Go to Start then Control Panel.
2. Click on Windows Update at the very bottom of control panel.
3. Now click on View Installed Updates, i'll open list of installed windows updates.
4. Find an update KB971033 and uninstall it by double clicking on it.

Problem is I don't seem to have the KB971033 update. Closest one I have to that is KB958488 (just says those letters and numbers and nothing else, was installed in 2012, pretty much all of the updates were installed at that time), and there's a 'Update for Microsoft Windows KB976902' (installed in 2010). Which one do I uninstall? KB958488 or KB976902? Also, what happens when I uninstall whichever one? Does the error go away for good?

The error means you are using pirated software. You need to buy a genuine copy of Windows 7.