Keyboard - Software

[Taurevanime]

I recently got a G15 keyboard after years of having used a keyboard that was offered for free with the PC I bought and I am very pleased with it. But I have hit one problem and try as I might I can not seem to fix it myself.

Whenever I use keys such as the " or ^ key, rather than just inserting the a single quotation mark or something it adds two of them in, sometimes it doesn't add one at all. It's not something serious just something annoying if you're trying to be punctual and type fast. What is odd is that when I boot up my system and type away it doesn't do this, it seems to only suddenly start happening after some time and then it just doesn't go away.

The OS I currently use is Windows XP Home Edition with Service Pack 3.

Any help would be appreciated, thank you.