returning trojan

Hello;
I have a trojan that i can't get rid of and can't find where it is re-installing from.
i haven't tried hijackthis before so i don't really know what it's all about ... hopefully someone can assist me a little

EDITED:
sorry ...forgot to include the log file info ... here it is ... and ... not sure if it matters but i ran the hijackthis program in safe mode:

Logfile of HijackThis v1.99.1
Scan saved at 10:30:00 PM, on 1/1/2007
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\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\Documents and Settings\USER\Desktop\New Folder (6)\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://us.rd.yahoo.com/customize/ie/defaults/sb/msgr8/*http://www.yahoo.com/ext/search/search.html
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = http://us.rd.yahoo.com/customize/ie/defaults/sp/msgr8/*http://www.yahoo.com
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.google.ca/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://www.yahoo.com/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://us.rd.yahoo.com/customize/ie/defaults/su/msgr8/*http://www.yahoo.com
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Bar = http://us.rd.yahoo.com/customize/ie/defaults/sb/msgr8/*http://www.yahoo.com/ext/search/search.html
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = http://us.rd.yahoo.com/customize/ie/defaults/sp/msgr8/*http://www.yahoo.com
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.yahoo.com/
R1 - HKCU\Software\Microsoft\Internet Explorer\SearchURL,(Default) = http://us.rd.yahoo.com/customize/ie/defaults/su/msgr8/*http://www.yahoo.com
R3 - URLSearchHook: Yahoo! Toolbar - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - (no file)
N4 - Mozilla: user_pref("browser.startup.homepage", "http://www.google.ca"); (C:\Documents and Settings\USER\Application Data\Mozilla\Profiles\default\3tlpxg2p.slt\prefs.js)
N4 - Mozilla: user_pref("browser.search.defaultengine", "engine://C%3A%5CProgram%20Files%5Cmozilla.org%5CMozilla%5Csearchplugins%5Cgoogle.src"); (C:\Documents and Settings\USER\Application Data\Mozilla\Profiles\default\3tlpxg2p.slt\prefs.js)
O2 - BHO: Adobe PDF Reader Link Helper - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 7.0\ActiveX\AcroIEHelper.dll
O2 - BHO: (no name) - {348FE907-249E-4C65-A838-F34A193FE1D1} - (no file)
O2 - BHO: (no name) - {53707962-6F74-2D53-2644-206D7942484F} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre1.5.0_09\bin\ssv.dll
O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE C:\WINDOWS\system32\NvCpl.dll,NvStartup
O4 - HKLM\..\Run: [SoundMan] SOUNDMAN.EXE
O4 - HKLM\..\Run: [nwiz] nwiz.exe /install
O4 - HKLM\..\Run: [AVG7_CC] C:\PROGRA~1\Grisoft\AVGFRE~1\avgcc.exe /STARTUP
O4 - HKLM\..\Run: [NvMediaCenter] RUNDLL32.EXE C:\WINDOWS\system32\NvMcTray.dll,NvTaskbarInit
O4 - HKLM\..\Run: [Lexmark X74-X75] "C:\Program Files\Lexmark X74-X75\lxbbbmgr.exe"
O4 - HKLM\..\Run: [WinampAgent] C:\Program Files\Winamp\winampa.exe
O4 - HKLM\..\Run: [MSConfig] C:\WINDOWS\PCHealth\HelpCtr\Binaries\MSConfig.exe /auto
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [UnHackMe Monitor] C:\Program Files\UnHackMe\hackmon.exe
O4 - Global Startup: VIA RAID TOOL.lnk = C:\Program Files\VIA\RAID\raid_tool.exe
O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:\PROGRA~1\MICROS~2\OFFICE11\EXCEL.EXE/3000
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_09\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_09\bin\ssv.dll
O16 - DPF: {04E214E5-63AF-4236-83C6-A7ADCBF9BD02} (HouseCall Control) - http://housecall60.trendmicro.com/housecall/xscan60.cab
O16 - DPF: {2BC66F54-93A8-11D3-BEB6-00105AA9B6AE} (Symantec AntiVirus scanner) - http://security.symantec.com/sscv6/SharedContent/vc/bin/AvSniff.cab
O16 - DPF: {39B0684F-D7BF-4743-B050-FDC3F48F7E3B} (FilePlanet Download Control Class) - http://www.fileplanet.com/fpdlmgr/cabs/FPDC_2.3.2.100.cab
O16 - DPF: {6414512B-B978-451D-A0D8-FCFDF33E833C} (WUWebControl Class) - http://v5.windowsupdate.microsoft.c...ls/en/x86/client/wuweb_site.cab?1112137079280
O16 - DPF: {644E432F-49D3-41A1-8DD5-E099162EEEC5} (Symantec RuFSI Utility Class) - http://security.symantec.com/sscv6/SharedContent/common/bin/cabsa.cab
O16 - DPF: {8E0D4DE5-3180-4024-A327-4DFAD1796A8D} (MessengerStatsClient Class) - http://messenger.zone.msn.com/binary/MessengerStatsClient.cab31267.cab
O16 - DPF: {9059F30F-4EB1-4BD2-9FDC-36F43A218F4A} (Microsoft RDP Client Control (redist)) - file://C:\WINDOWS\Web\TSWeb\msrdp.cab
O16 - DPF: {9A9307A0-7DA4-4DAF-B042-5009F29E09E1} (ActiveScan Installer Class) - http://acs.pandasoftware.com/activescan/as5free/asinst.cab
O16 - DPF: {DF780F87-FF2B-4DF8-92D0-73DB16A1543A} - http://www.shockwave.com/content/bejeweled2/popcaploader_v6.cab
O17 - HKLM\System\CCS\Services\Tcpip\..\{5D73CDD3-60F9-4877-914F-1130A452E8EE}: NameServer = 64.59.135.133,64.59.135.135
O17 - HKLM\System\CCS\Services\Tcpip\..\{DC341580-AB20-4AAF-8B2F-287E5898376F}: NameServer = 64.59.135.133,64.59.135.135
O18 - Protocol: msnim - {828030A1-22C1-4009-854F-8E305202313F} - "C:\PROGRA~1\MSNMES~1\msgrapp.dll" (file missing)
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: AVG E-mail Scanner (AVGEMS) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVGFRE~1\avgemc.exe