I really don't see much in the HJT log, some extra's running at start up which are not necessary;
QuickTime Task
RealPlayer Update
iTunes
AIM.
None of those need to run at start and can be run manually if needed.
I recommend using Mike Lin's StartUpControlPanel to control auto starts.
You might take a look at ~ TL's link How to configure Windows Services in XP
to disable some unnecessary starts that all XP systems have running. This should speed things up quite a bit.
As for those items in Add/Remove that you can't identify, they all are legitimate programs;
IrfanView>>>photo editor
Learnout & Hauspie truVoice American English TTS Engine>>>A computerized system and method of teaching spelling interfaces with an application that captures a user's misspelled words and adds them to a word database
OmniPass>>>application that can be used by consumers and enterprises to securely login to websites and applications (SSO) as well as protect data on a PC
.PS2>>>Playstation2
Python2>>>object-oriented programming language
S3 Display>>>Graphics Display driver
S3 Gamma2>>>Graphics
s3 Info 2>>>graphics
S3 Overlay>>>graphics overlay utility
ShowBiz DVD>>>video editor
SimpleBackup for my pictures>>>back up utility for photos
Simple installer>>>system tool

It appears that AVG cleaned up the screensaver problem.
KillWind found by the Kaspersky scan is not a virus. It came pre-installed on your PC by HP when you first purchased it. This is what is known as a "false positive".