Windows 7 behaving as if shift key is depressed

I had nearly the same exact problem except that I would get upper case letters when typing. I tried everything I could think of to get it fixed. What wound up fixing the issue for me was opening up the onscreen keyboard. I have no idea why this worked.

You may want to check you've not accidentally turned on Sticky Keys ("Control Panel" -> "Ease of Access Center" or "Accessibility" (depending on your Windows version), then kick on the option for "Sticky Keys", and make sure it's not turned on).

This is a software problem, not a hardware problem. I've done this before, though I don't know how, and the easiest way to fix it is by:

• Going to the Control Panel;
• Going to the "Ease of Access" or "Accessibility" center;
• Clicking on "Change How Your Keyboard Works";
• Making sure that the box next to "Sticky Keys" isn't checked (so Sticky Keys isn't turned on);
• Scrolling to the bottom and clicking on "Keyboard Settings";
• Then in the window that opens, going to the "Buttons" tab at the top, clicking on "Restore Defaults";
• Clicking "Apply", then "OK" and doing the same ("Apply", then "OK") in the original window.

This should fix the problem. It'll override whatever it was that you did to make your keyboard think the shift key was pressed down.