Spyware/Trojan?

Ok, so I go on my parents PC to give it a quick tune-up, and I get "Click YES to install the software" out of the blue. Not even with IE apparently open. So i go through the task manager, end likley looking tasks (obviously IE processes first) and come across which called itself TCPService.exe, which made the box dissapear. Hmm, i thought. So, I suspect this machine has a trojan. So I downloaded The Cleaner and its still scanning as I type.
Here is an excert from my HijackThis log, and attached is the full log.

Logfile of HijackThis v1.97.7
Scan saved at 22:11:47, on 05/06/2004
Platform: Windows XP SP1 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP1 (6.00.2800.1106)

Running processes:
C:\WINDOWS\System32\smss.exe
C:\WINDOWS\system32\winlogon.exe
C:\WINDOWS\system32\services.exe
C:\WINDOWS\system32\lsass.exe
C:\WINDOWS\System32\Ati2evxx.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\Ati2evxx.exe
C:\WINDOWS\Explorer.EXE


They all seem pretty normal to me! I got a few hits on Pestscan.com, but mostly because spybot had immunised against a load of dodgey websites already.. which is what set it off. This machine is fully patched with updates .. antivirus is up to date, as is adaware and spybot, and scanned with all. I'm also still scanning with The Cleaner. I have Panda AV by the way... hopefully to change to avast! after testing it on my machine.

Hmmmm....

EDIT : The Cleaner comes up with no hits :/

 

Hmm, interesting, I ran crap cleaner just now as well.. and I'm going to leave the machine on for a while and see if the problem comes back after a restart and a few hours idle (when i go to sleep).

 

Well, the problem seems to have gone away, but I didnt have the chance to test it overnight as my parents turned the machine off grr.

But yeah, Ive got Crap Cleaner on there and did a sweep with it. Maybe it was some errant temp file or somthing :/ hmm ...