Hello and welcome to Bleepingcomputer.
I wanted to reply to you because I did not want you to feel like you were talking to yourself.
I want to ask if you have ever tried running MalwareBytes Anti-Malware?
There could still be some hidden Malware on your hard drive.
Mawarebytes Anti malware http://www.malwarebytes.org/
Download the free version, update and do a FULL scan.
The problems with most computers after they become infected with Malware is the windows registry ends up with corrupted files that Malware tends to change, alter or delete.
I do not recommend the use of registry cleaners to resolve this problem.
One resolution I have found that works is installing the OS over its self.
This is however, successfully accomplished only when the operating system was installed using a retail version of the OS. In your case Windows XP Professional.
If you have the Windows XP Pro installation disk please let me know.
OEM OS installation disks work differently and different procedures have to be used.