Yes, the easiest way to turn of the windows key is to use microsoft Fixit.
[h=2]Automated method[/h]
Disable the Windows key Step 1: Download the Microsoft Fix it program 50465 from Microsoft at
http://go.microsoft.com/?linkid=9738719.
Step 2: Double-click on the file you just downloaded,
MicrosoftFixit50465.msi, and click
Run to install the fix.
Step 3: Follow the short installation prompts and restart your computer.
(Credit: Screenshot by Ed Rhee)
Enable the Windows key Step 1: Download the Microsoft Fix it program 50464 from Microsoft at
http://go.microsoft.com/?linkid=9738718.
Step 2: Double-click on the file you just downloaded,
MicrosoftFixit50464.msi, and click
Run to install the fix.
Step 3: Follow the short installation prompts and restart your computer.
But have you checked that some how the windows key is stucked by maybe a piece of debris.?
If it is somehow software or system related maybe you can first disable it and later enable it again to see if will work normally again.