I have tried rebooting in safe modus and removing the file in System32 (sorry, I'm a noob - I forgot the name but rest assured it was the oneclicksearch one, nothing else )
Anyway, I would be extremely grateful for any help - let me know if there's more information you need or anything.
Here's my latest Hijack This logfile:
Logfile of HijackThis v1.99.1
Scan saved at 19:06:41, on 6-8-2005
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP2 (6.00.2900.2180)
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\Ati2evxx.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\system32\shnlog.exe
C:\Program Files\Network Associates\VirusScan\Avsynmgr.exe
C:\Program Files\ewido\security suite\ewidoctrl.exe
C:\Program Files\ewido\security suite\ewidoguard.exe
C:\Program Files\Network Associates\VirusScan\VsStat.exe
C:\Program Files\Analog Devices\SoundMAX\SMAgent.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\ZoneLabs\vsmon.exe
C:\Program Files\Network Associates\VirusScan\Avconsol.exe
C:\WINDOWS\System32\imapi.exe
C:\hijackthis\HijackThis.exe
C:\WINDOWS\system32\intmon.exe
C:\WINDOWS\system32\wuauclt.exe
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = about:blank
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://www.oneclicks...earch.php?qq=%1
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://www.oneclicks...es.com/bar.html
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = http://www.oneclicks...earch.php?qq=%1
R1 - HKCU\Software\Microsoft\Internet Explorer\Search,SearchAssistant = http://www.oneclicks...earch.php?qq=%1
R1 - HKCU\Software\Microsoft\Internet Explorer\Search,CustomizeSearch = http://www.oneclicks...earch.php?qq=%1
R1 - HKCU\Software\Microsoft\Internet Explorer\SearchURL,(Default) = http://www.oneclicks...earch.php?qq=%1
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Local Page = http://www.oneclicksearches.com/
O2 - BHO: HP Class - {FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFA} - C:\WINDOWS\system32\hp5091.tmp
O4 - HKLM\..\Run: [PSGuard] C:\Program Files\PSGuard\PSGuard.exe
O4 - HKCU\..\Run: [MSMSGS] "C:\Program Files\Messenger\msmsgs.exe" /background
O23 - Service: Ati HotKey Poller - Unknown owner - C:\WINDOWS\System32\Ati2evxx.exe
O23 - Service: AVSync Manager (AvSynMgr) - Unknown owner - C:\Program Files\Network Associates\VirusScan\Avsynmgr.exe
O23 - Service: ewido security suite control - ewido networks - C:\Program Files\ewido\security suite\ewidoctrl.exe
O23 - Service: ewido security suite guard - ewido networks - C:\Program Files\ewido\security suite\ewidoguard.exe
O23 - Service: SoundMAX Agent Service (SoundMAX Agent Service (default)) - Analog Devices, Inc. - C:\Program Files\Analog Devices\SoundMAX\SMAgent.exe
O23 - Service: TrueVector Internet Monitor (vsmon) - Zone Labs Inc. - C:\WINDOWS\system32\ZoneLabs\vsmon.exe