After making a post in the HijackThis Forums, they helped me and redirected me to this forum. My PC seems to be clear of all malware, so I'm hoping you guys would have some information on my odd problem.
First of all, I made sure the keyboard and mouse weren't faulty. I tested the same keyboard/mouse on a different computer, and they worked perfectly fine. If the mouse is being moved or clicked, keyboard input is completely ignored by the PC. So I have to completely stop moving the mouse in order to type.
I am running Windows XP Professional SP2. I've ensured all keyboard/mouse drivers and windows updates were up to date.
Thank you for your time^^