I've tried using Spybot S&D, Adaware 6, Spy Remover, CWShredder....and no real joy.

Here's my HJT logfile; please help, I'm at my wits end here!

Logfile of HijackThis v1.97.7
Scan saved at 9:13:57 AM, on 14/08/2004
Platform: Windows XP (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 (6.00.2600.0000)

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:\PROGRA~1\Grisoft\AVG6\avgserv.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\Microsoft Hardware\Mouse\point32.exe
C:\WINDOWS\SOUNDMAN.EXE
C:\Program Files\Microsoft Hardware\Keyboard\type32.exe
C:\PROGRA~1\Grisoft\AVG6\avgcc32.exe
C:\Program Files\ATI Technologies\ATI Control Panel\atiptaxx.exe
C:\Program Files\MSN Apps\Updater\01.02.0002.1001\en-au\msnappau.exe
C:\Program Files\Adobe\Acrobat 5.0\Distillr\AcroTray.exe
C:\Documents and Settings\All Users\Start Menu\Programs\Startup\winlgn.exe
C:\Program Files\WinZip\WZQKPICK.EXE
C:\Program Files\Internet Explorer\IEXPLORE.EXE
D:\HJT\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://youriskalka.com/sp.htm
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = http://youriskalka.com/index.htm
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://youriskalka.com/index.htm
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://www.iprimus.com.au
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant = http://youriskalka.com/sp.htm
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Window Title = BigPond Dial-Up Residential Internet Explorer
R1 - HKCU\Software\Microsoft\Internet Explorer\SearchURL,(Default) = http://youriskalka.com/index.htm
O2 - BHO: (no name) - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 5.0\Acrobat\ActiveX\AcroIEHelper.ocx
O2 - BHO: (no name) - {53707962-6F74-2D53-2644-206D7942484F} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O2 - BHO: (no name) - {9394EDE7-C8B5-483E-8773-474BF36AF6E4} - C:\Program Files\MSN Apps\ST\01.02.0002.1001\en-xu\stmain.dll
O2 - BHO: (no name) - {AA58ED58-01DD-4d91-8333-CF10577473F7} - c:\windows\googletoolbar.dll (file missing)
O2 - BHO: (no name) - {BDBD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\MSN Apps\MSN Toolbar\01.02.2001.0001\en-au\msntb.dll
O3 - Toolbar: &Radio - {8E718888-423F-11D2-876E-00A0C9082467} - C:\WINDOWS\System32\msdxm.ocx
O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - c:\windows\googletoolbar.dll (file missing)
O3 - Toolbar: Easy-WebPrint - {327C2873-E90D-4c37-AA9D-10AC9BABA46C} - C:\Program Files\Canon\Easy-WebPrint\Toolband.dll
O3 - Toolbar: ninemsn - {BDAD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\MSN Apps\MSN Toolbar\01.02.2001.0001\en-au\msntb.dll
O4 - HKLM\..\Run: [POINTER] point32.exe
O4 - HKLM\..\Run: [SoundMan] SOUNDMAN.EXE
O4 - HKLM\..\Run: [NeroCheck] C:\WINDOWS\System32\\NeroCheck.exe
O4 - HKLM\..\Run: [IntelliType] "C:\Program Files\Microsoft Hardware\Keyboard\type32.exe"
O4 - HKLM\..\Run: [AVG_CC] C:\PROGRA~1\Grisoft\AVG6\avgcc32.exe /STARTUP
O4 - HKLM\..\Run: [ATIPTA] C:\Program Files\ATI Technologies\ATI Control Panel\atiptaxx.exe
O4 - HKLM\..\Run: [msnappau] "C:\Program Files\MSN Apps\Updater\01.02.0002.1001\en-au\msnappau.exe"
O4 - HKLM\..\Run: [Zone Labs Client] "C:\Program Files\Zone Labs\ZoneAlarm\zlclient.exe"
O4 - HKCU\..\Run: [MsnMsgr] "C:\Program Files\MSN Messenger\MsnMsgr.Exe" /background
O4 - Global Startup: Acrobat Assistant.lnk = C:\Program Files\Adobe\Acrobat 5.0\Distillr\AcroTray.exe
O4 - Global Startup: Microsoft Office.lnk = C:\Program Files\Microsoft Office\Office10\OSA.EXE
O4 - Global Startup: winlgn.exe
O4 - Global Startup: WinZip Quick Pick.lnk = C:\Program Files\WinZip\WZQKPICK.EXE
O8 - Extra context menu item: &Google Search - res://C:\WINDOWS\GoogleToolbar.dll/cmsearch.html
O8 - Extra context menu item: Backward &Links - res://C:\WINDOWS\GoogleToolbar.dll/cmbacklinks.html
O8 - Extra context menu item: Cac&hed Snapshot of Page - res://C:\WINDOWS\GoogleToolbar.dll/cmcache.html
O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:\PROGRA~1\MICROS~3\Office10\EXCEL.EXE/3000
O8 - Extra context menu item: Easy-WebPrint Add To Print List - res://C:\Program Files\Canon\Easy-WebPrint\Resource.dll/RC_AddToList.html
O8 - Extra context menu item: Easy-WebPrint High Speed Print - res://C:\Program Files\Canon\Easy-WebPrint\Resource.dll/RC_HSPrint.html
O8 - Extra context menu item: Easy-WebPrint Preview - res://C:\Program Files\Canon\Easy-WebPrint\Resource.dll/RC_Preview.html
O8 - Extra context menu item: Easy-WebPrint Print - res://C:\Program Files\Canon\Easy-WebPrint\Resource.dll/RC_Print.html
O8 - Extra context menu item: Si&milar Pages - res://C:\WINDOWS\GoogleToolbar.dll/cmsimilar.html
O8 - Extra context menu item: Translate Page - res://C:\WINDOWS\GoogleToolbar.dll/cmtrans.html
O9 - Extra button: Messenger (HKLM)
O9 - Extra 'Tools' menuitem: Windows Messenger (HKLM)
O12 - Plugin for .mpeg: C:\Program Files\Internet Explorer\PLUGINS\npqtplugin3.dll
O12 - Plugin for .spop: C:\Program Files\Internet Explorer\Plugins\NPDocBox.dll
O14 - IERESET.INF: START_PAGE_URL=http://www.iprimus.com.au
O16 - DPF: {8E0D4DE5-3180-4024-A327-4DFAD1796A8D} (MessengerStatsClient Class) - http://messenger.zone.msn.com/binary/MessengerStatsClient.cab28578.cab
O16 - DPF: {8EDAD21C-3584-4E66-A8AB-EB0E5584767D} - http://toolbar.google.com/data/GoogleActivate.cab
O16 - DPF: {9A9307A0-7DA4-4DAF-B042-5009F29E09E1} (ActiveScan Installer Class) - http://www.pandasoftware.com/activescan/as5/asinst.cab
O16 - DPF: {9F1C11AA-197B-4942-BA54-47A8489BB47F} (Update Class) - http://v4.windowsupdate.microsoft.com/CAB/x86/unicode/iuctl.CAB?37884.8420023148
O16 - DPF: {A8658086-E6AC-4957-BC8E-7D54A7E8A78E} - http://www.microsoft.com/security/controls/SassCln.CAB
O16 - DPF: {D27CDB6E-AE6D-11CF-96B8-444553540000} (Shockwave Flash Object) - http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab
O16 - DPF: {F6BF0D00-0B2A-4A75-BF7B-F385591623AF} (Solitaire Showdown Class) - http://messenger.zone.msn.com/binary/SolitaireShowdown.cab28578.cab
O17 - HKLM\System\CCS\Services\Tcpip\..\{619AD495-783C-4408-85AF-EBC0AECAB25B}: NameServer = 203.194.27.57 203.194.56.150