Keys turn into shortcut keys even though windows key is disabled

[mikacg]

Hello.

I'm a Windows 7 user and a few months ago, I've changed my laptop's keyboard (hardware) into a new one because some keys were malfunctioned. At first, everything seems fine but soon the keys started to going crazy. Some keys turned to shortcut keys (like opening a new window, open the control panel, etc) or freezed the screen . I don't know whether this got to do with malware or because it has a conflict with other program. After I changed to that new keyboard, I uninstalled some programs, bought and downloaded Microsoft Office 2016 and Malwarebytes Premium 3.0. The problem getting worse so I decided to restore the system. At first, it worked well but later, the same problem came back again. After googling for some help, I found out that my windows key is always stuck (though it seems didn't stuck physically) whenever I open the on-screen keyboard. So I downloaded SharpKeys to disable/turn off the windows key and I confirmed that the key didn't stick on the screen keyboard anymore. But, 'magically', my problem isn't solved yet. Sometimes, the short keys pop up randomly when I type the key *sigh* I have to restart my laptop a few times to make it better. 

Help me please...