Hi Scryll !! (aka my hardest target in Battle)
Is that particular unit on dynamic, or staic IP, rather what is the DNS server entries? Does it match the other computers in the house?
An alternative to Panda, seen it, at client sites, did not particularly care for it myself, but that does not matter, what does matter is you have an anti-virus installed, and it is regularly updated. I use AVG FREE myself, been using it for years actually.
Is it only browsing that is slow? or is ANYTHING online slow? ( like remote access or Hamachi or other apps/games/programs that do not interface with your browser)
Have you done the delete temporary files in IE (assuminig that is what your using) and the disk cleanup on the hdd in question?
Another quick thing to try is IPCONFIG /dnsflush, that MAY help, not knowing anything else about the problem...something to try anyways...it only takes 10 seconds)
And yea, these posts should be in the computer help forum, but hey... It does not matter where the advice comes from, as long as it IS good advice!!!
Let us know what comes of this, I would be interested to know what it is/was causing the slow down.
May your bits flow freely, and quickly !!