Hi adion, welcome to DaniWeb :D
Your system most likely has been severely compromised; can you use System Restore to return it to a date before you were infected? ( http://securityresponse.symantec.com/avcenter/venc/data/hacktool.rootkit.html ) You may need to consider reinstalling XP; if you do, get SP2 as soon as possible thereafter.
You can try the following to see if it helps any:
Go to Windows Update and get SP1a for both XP and IE.
Check for, and delete, the files listed here:
http://vil.mcafeesecurity.com/vil/content/v_102335.htm
Go to Start, Run, and type in services.msc; when the Services window opens, disable (for the time being at least) any entries that say Remote Access... (To disable them, first right-click on the entry, go to Properties, and next to Startup type, use the drop-down arrow and select Disable.
Scan with hijackthis and have it fix the following entries:
O9 - Extra button: Related - {c95fe080-8f5d-11d2-a20b-00aa003c157a} - E:\WINDOWS\web\related.htm
O9 - Extra 'Tools' menuitem: Show &Related Links - {c95fe080-8f5d-11d2-a20b-00aa003c157a} - E:\WINDOWS\web\related.htm
For every User listed under C:\Documents and Settings, delete the entire contents of these folders (not the folders themselves):
Local Settings\Temp
Cookies
History
Local Settings\Temporary Internet Files\Content.IE5
Delete the entire contents of your C:\Windows\Temp folder.
Delete the entire contents of your C:\Temp folder (if you have one).
Do a search for *.tmp and delete all entries found.
(Note: if any of these temporary files cannot be deleted while in ‘normal mode,’ try Safe Mode.
Empty your Recycle Bin.
Cross your fingers, reboot, and see if there is any improvement.
