My computer is acting up?

my comp will only open up a few web pages sometimes,its saying the page has expired,was fine about a week ago and now this what should i look for,security settings havent changed,at least i dont think they have,its a e-machine,windows xp

My computer is acting up?norton antivirus

Download AVG anti spy and avg anti virus. After those programs are done removing all the infections your pc.c obviously has, then defrag the hard drive, By going to Star,all programs, accesories, system tools, defrag. Here's the link, these programs are free.

http://free.grisoft.com/doc/1

My computer is acting up?security

depends on your internet settings. email me about your internet settings and i will help you.my tip is dont use IE, use firefix or opera theyre safer and easier and better
MINE WAS ACTING UP AND IT COST ME $50.00 AND ITS STILL ACTING UP. I WILL RETURN TO THE COMPUTER SHOP TOMORROW
Use your recovery disc if u have one, it may help.
Have you been loading up the latest updates on you Norton protection (current one)?, than scanning your computer on a weekly basis (same day around same time so you remember)? Please try that (it might solve your situation).
404 refresh...Use a different browser...Try Opera.
try removing internet temp files and cookies etc, that may prevent it from happening. Use a small program AFT cleaner for it.

http://bestofrest.blogspot.com/2006/12/a...
try doing a system restore