I have used Ad-aware and Spybot S&D as recommended on this site - which pick up various components but are unable to remove them permanantly.
Anyway, here's the hijackthis log:
Logfile of HijackThis v1.99.1
Scan saved at 4:56:43 PM, on 8/05/2005
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\Ati2evxx.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\system32\spoolsv.exe
C:\PROGRA~1\Grisoft\AVGFRE~1\avgamsvr.exe
C:\PROGRA~1\Grisoft\AVGFRE~1\avgupsvc.exe
C:\Program Files\Common Files\Microsoft Shared\VS7Debug\mdm.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\ZoneLabs\vsmon.exe
C:\WINDOWS\System32\msole32.exe
C:\WINDOWS\popuper.exe
C:\WINDOWS\System32\shnlog.exe
C:\PROGRA~1\Grisoft\AVGFRE~1\avgcc.exe
C:\PROGRA~1\Grisoft\AVGFRE~1\avgemc.exe
C:\Program Files\Zone Labs\ZoneAlarm\zlclient.exe
C:\Program Files\Telstra\Toolbar\bpumTray.exe
C:\WINDOWS\System32\intmonp.exe
C:\Program Files\Telstra\Cable Login\bpcable.exe
C:\WINDOWS\System32\intmon.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\WINDOWS\System32\wuauclt.exe
C:\HJT\HijackThis.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.quicknavi...earch.php?qq=%1
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://www.quicknavigate.com/bar.html
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = http://www.quicknavi...earch.php?qq=%1
R1 - HKCU\Software\Microsoft\Internet Explorer\Search,SearchAssistant = http://www.quicknavi...earch.php?qq=%1
R1 - HKCU\Software\Microsoft\Internet Explorer\Search,CustomizeSearch = http://www.quicknavi...earch.php?qq=%1
R1 - HKCU\Software\Microsoft\Internet Explorer\SearchURL,(Default) = http://www.quicknavi...earch.php?qq=%1
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Local Page = http://www.quicknavigate.com/
F2 - REG:system.ini: Shell=explorer.exe, msmsgs.exe
O2 - BHO: VMHomepage Class - {FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF} - C:\WINDOWS\System32\hp57B4.tmp
O3 - Toolbar: &Radio - {8E718888-423F-11D2-876E-00A0C9082467} - C:\WINDOWS\System32\msdxm.ocx
O4 - HKLM\..\Run: [AVG7_CC] C:\PROGRA~1\Grisoft\AVGFRE~1\avgcc.exe /STARTUP
O4 - HKLM\..\Run: [AVG7_EMC] C:\PROGRA~1\Grisoft\AVGFRE~1\avgemc.exe
O4 - HKLM\..\Run: [Zone Labs Client] "C:\Program Files\Zone Labs\ZoneAlarm\zlclient.exe"
O4 - HKLM\..\Run: [BigPond Toolbar] "C:\Program Files\Telstra\Toolbar\bpumTray.exe"
O4 - HKLM\..\Run: [BigPondCable] "C:\Program Files\Telstra\Cable Login\bpcable.exe" /r
O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:\PROGRA~1\MICROS~2\Office10\EXCEL.EXE/3000
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_01\bin\npjpi150_01.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_01\bin\npjpi150_01.dll
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\MSMSGS.EXE
O9 - Extra 'Tools' menuitem: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\MSMSGS.EXE
O15 - Trusted Zone: *.musicmatch.com
O15 - Trusted Zone: *.musicmatch.com (HKLM)
O23 - Service: Ati HotKey Poller - ATI Technologies Inc. - C:\WINDOWS\System32\Ati2evxx.exe
O23 - Service: ATI Smart - Unknown owner - C:\WINDOWS\system32\ati2sgag.exe
O23 - Service: AVG7 Alert Manager Server (Avg7Alrt) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVGFRE~1\avgamsvr.exe
O23 - Service: AVG7 Update Service (Avg7UpdSvc) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVGFRE~1\avgupsvc.exe
O23 - Service: BigPond Broadband Cable Login (bpcService) - Unknown owner - C:\Program Files\Telstra\Cable Login\bpcService.exe
O23 - Service: TrueVector Internet Monitor (vsmon) - Zone Labs LLC - C:\WINDOWS\system32\ZoneLabs\vsmon.exe
/log
Thanks in advance