This system is seriously infected, and there's several reasons why.
You have no Anti Virus protection program.
Your Windows XP is unpatched,

leaving all the security flaws available for malware to exploit. Windows XP is at Service Pack 2,and has been for a couple of years now, meaning there are many patches even beyond SP2 that are open to exploit on this system.
Can you use Safe Mode with Networking on this machine? Are you posting from the infected machine, or another? This will determine the approach taken.
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Practice Safe Surfing
Because what you don't know, CAN hurt you.
Proud Member of ASAP since 2005
Proud Member of UNITE since 2006