Oh and from your first post it could even be a keyboard problem, someone spill tea on it and not tell you perhaps?
totally agree, my housemate had the same problem, ebuyer is good for cheap kb's if you need one, i agree with the norton comment aswell, get panda or something, cos there is hearsay that norton release viruses that only they know how to kill, making money in the process. plus may sound silly, but when was the last time you deleted your cookies and tempory folders?
do that by going to "start" "control panel" "internet options" then "delete cookies" and "delete files"