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:\Program Files\Common Files\Symantec Shared\ccProxy.exe
C:\Program Files\Common Files\Symantec Shared\ccSetMgr.exe
C:\Program Files\Norton Internet Security\ISSVC.exe
C:\Program Files\Common Files\Symantec Shared\SNDSrvc.exe
C:\Program Files\Common Files\Symantec Shared\SPBBC\SPBBCSvc.exe
C:\Program Files\Common Files\Symantec Shared\ccEvtMgr.exe
C:\WINDOWS\system32\LEXBCES.EXE
C:\WINDOWS\system32\LEXPPS.EXE
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\Norton Internet Security\Norton AntiVirus\navapsvc.exe
C:\Program Files\Common Files\Symantec Shared\CCPD-LC\symlcsvc.exe
C:\Program Files\RealVNC\WinVNC\WinVNC.exe
C:\WINDOWS\essspk.exe
C:\WINDOWS\System32\keyhook.exe
C:\Program Files\MSN Apps\Updater\01.02.3000.1001\en-us\msnappau.exe
C:\Program Files\EPoX\USDM\USDM.EXE
C:\Program Files\Messenger Plus! 3\MsgPlus.exe
C:\WINDOWS\vsnpt513.exe
C:\Program Files\Common Files\Real\Update_OB\realsched.exe
C:\PROGRA~1\ntl\BROADB~1\SMARTB~1\MotiveSB.exe
C:\WINDOWS\SOUNDMAN.EXE
C:\Program Files\Common Files\Symantec Shared\ccApp.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Yahoo!\Messenger\ypager.exe
C:\Program Files\MSN Messenger\msnmsgr.exe
C:\WINDOWS\system32\sistray.exe
C:\Program Files\MUSTEK 1248UB\Driver\WATCH.exe
C:\Program Files\ntl\broadband medic\bin\mpbtn.exe
C:\Program Files\MSN\MSNCoreFiles\MSN6.EXE
C:\Program Files\Internet Explorer\iexplore.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\Program Files\Common Files\Symantec Shared\AdBlocking\NSMdtr.exe
C:\Program Files\Messenger\msmsgs.exe
C:\Documents and Settings\User\Local Settings\Temporary Internet Files\Content.IE5\I3WBYDGJ\hijackthis[1].exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://uk.red.clientapps.yahoo.com/c...o/bt_side.html
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = http://uk.red.clientapps.yahoo.com/c...ww.yahoo.co.uk
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.ntlworld.com/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://uk.red.clientapps.yahoo.com/c...ww.yahoo.co.uk
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Bar = http://uk.red.clientapps.yahoo.com/c...o/bt_side.html
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = http://uk.red.clientapps.yahoo.com/c...ww.yahoo.co.uk
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Int ernet Settings,ProxyOverride = 127.0.0.1
R3 - URLSearchHook: (no name) - {CA0E28FA-1AFD-4C21-A8DC-70EB5BE2F076} - (no file)
F2 - REG:system.ini: UserInit=C:\WINDOWS\System32\Userinit.exe
O2 - BHO: Yahoo! Companion BHO - {02478D38-C3F9-4efb-9B51-7695ECA05670} - C:\PROGRA~1\Yahoo!\COMPAN~1\Installs\cpn0\ycomp5_3 _12_0.dll
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 5.0\Reader\ActiveX\AcroIEHelper.ocx
O2 - BHO: (no name) - {53707962-6F74-2D53-2644-206D7942484F} - C:\Program Files\Spybot - Search & Destroy\SDHelper.dll
O2 - BHO: Search404 Class - {53C330D6-A4AB-419B-B45D-FD4411C1FEF4} - C:\Program Files\404Search\404Search.dll
O2 - BHO: ST - {9394EDE7-C8B5-483E-8773-474BF36AF6E4} - C:\Program Files\MSN Apps\ST\01.02.3000.1002\en-xu\stmain.dll
O2 - BHO: Norton Internet Security - {9ECB9560-04F9-4bbc-943D-298DDF1699E1} - C:\Program Files\Common Files\Symantec Shared\AdBlocking\NISShExt.dll
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - c:\program files\google\googletoolbar1.dll
O2 - BHO: MSNToolBandBHO - {BDBD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\MSN Apps\MSN Toolbar\01.02.3000.1001\en-us\msntb.dll
O2 - BHO: NAV Helper - {BDF3E430-B101-42AD-A544-FADC6B084872} - C:\Program Files\Norton Internet Security\Norton AntiVirus\NavShExt.dll
O3 - Toolbar: &Yahoo! Companion - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\PROGRA~1\Yahoo!\COMPAN~1\Installs\cpn0\ycomp5_3 _12_0.dll
O3 - Toolbar: MSN - {BDAD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\MSN Apps\MSN Toolbar\01.02.3000.1001\en-us\msntb.dll
O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - c:\program files\google\googletoolbar1.dll
O3 - Toolbar: Norton Internet Security - {0B53EAC3-8D69-4b9e-9B19-A37C9A5676A7} - C:\Program Files\Common Files\Symantec Shared\AdBlocking\NISShExt.dll
O3 - Toolbar: Norton AntiVirus - {42CDD1BF-3FFB-4238-8AD1-7859DF00B1D6} - C:\Program Files\Norton Internet Security\Norton AntiVirus\NavShExt.dll
O4 - HKLM\..\Run: [EssSpkPhone] essspk.exe
O4 - HKLM\..\Run: [SiSUSBRG] C:\WINDOWS\SiSUSBrg.exe
O4 - HKLM\..\Run: [SiS Windows KeyHook] C:\WINDOWS\System32\keyhook.exe
O4 - HKLM\..\Run: [msnappau] "C:\Program Files\MSN Apps\Updater\01.02.3000.1001\en-us\msnappau.exe"
O4 - HKLM\..\Run: [EPoXUSDM] "C:\Program Files\EPoX\USDM\USDM.EXE" "5000"
O4 - HKLM\..\Run: [MessengerPlus3] "C:\Program Files\Messenger Plus! 3\MsgPlus.exe"
O4 - HKLM\..\Run: [SNPT513] C:\WINDOWS\vsnpt513.exe
O4 - HKLM\..\Run: [TkBellExe] "C:\Program Files\Common Files\Real\Update_OB\realsched.exe" -osboot
O4 - HKLM\..\Run: [Motive SmartBridge] C:\PROGRA~1\ntl\BROADB~1\SMARTB~1\MotiveSB.exe
O4 - HKLM\..\Run: [SoundMan] SOUNDMAN.EXE
O4 - HKLM\..\Run: [ccApp] "C:\Program Files\Common Files\Symantec Shared\ccApp.exe"
O4 - HKLM\..\Run: [Symantec NetDriver Monitor] C:\PROGRA~1\SYMNET~1\SNDMon.exe
O4 - HKCU\..\Run: [Yahoo! Pager] C:\Program Files\Yahoo!\Messenger\ypager.exe -quiet
O4 - HKCU\..\Run: [MessengerPlus3] "C:\Program Files\Messenger Plus! 3\MsgPlus.exe" /WinStart
O4 - HKCU\..\Run: [msnmsgr] "C:\Program Files\MSN Messenger\msnmsgr.exe" /background
O4 - Global Startup: broadband medic.lnk = C:\Program Files\ntl\broadband medic\bin\matcli.exe
O4 - Global Startup: Utility Tray.lnk = C:\WINDOWS\system32\sistray.exe
O4 - Global Startup: Watch.lnk = C:\Program Files\MUSTEK 1248UB\Driver\WATCH.exe
O8 - Extra context menu item: &Google Search - res://c:\program files\google\GoogleToolbar1.dll/cmsearch.html
O8 - Extra context menu item: &Yahoo! Search - file:///C:\Program Files\Yahoo!\Common/ycsrch.htm
O8 - Extra context menu item: Backward Links - res://c:\program files\google\GoogleToolbar1.dll/cmbacklinks.html
O8 - Extra context menu item: Cached Snapshot of Page - res://c:\program files\google\GoogleToolbar1.dll/cmcache.html
O8 - Extra context menu item: Similar Pages - res://c:\program files\google\GoogleToolbar1.dll/cmsimilar.html
O8 - Extra context menu item: Translate into English - res://c:\program files\google\GoogleToolbar1.dll/cmtrans.html
O8 - Extra context menu item: Web Rebates - file://C:\Program Files\Web_Rebates\Sy1150\Tp1150\scri1150a.htm
O8 - Extra context menu item: Yahoo! &Dictionary - file:///C:\Program Files\Yahoo!\Common/ycdict.htm
O9 - Extra button: Messenger - {4528BBE0-4E08-11D5-AD55-00010333D0AD} - C:\Program Files\Yahoo!\Messenger\yhexbmes0527.dll
O9 - Extra 'Tools' menuitem: Yahoo! Messenger - {4528BBE0-4E08-11D5-AD55-00010333D0AD} - C:\Program Files\Yahoo!\Messenger\yhexbmes0527.dll
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O12 - Plugin for .spop: C:\Program Files\Internet Explorer\Plugins\NPDocBox.dll
O16 - DPF: Yahoo! Chat - http://us.chat1.yimg.com/us.yimg.com.../c381/chat.cab
O16 - DPF: {1D4DB7D2-6EC9-47A3-BD87-1E41684E07BB} - http://ak.imgfarm.com/images/nocache...tup1.0.0.8.cab
O16 - DPF: {205FF73B-CA67-11D5-99DD-444553540000} (CInstall Class) - http://www.spywarestormer.com/files2/Install.cab
O16 - DPF: {2BC66F54-93A8-11D3-BEB6-00105AA9B6AE} (Symantec AntiVirus scanner) - http://security.symantec.com/sscv6/S...in/AvSniff.cab
O16 - DPF: {644E432F-49D3-41A1-8DD5-E099162EEEC5} (Symantec RuFSI Utility Class) - http://security.symantec.com/sscv6/S.../bin/cabsa.cab
O16 - DPF: {9A9307A0-7DA4-4DAF-B042-5009F29E09E1} (ActiveScan Installer Class) - http://www.pandasoftware.com/activescan/as5/asinst.cab
O16 - DPF: {B38870E4-7ECB-40DA-8C6A-595F0A5519FF} (MsnMessengerSetupDownloadControl Class) - http://messenger.msn.com/download/Ms...Downloader.cab
O16 - DPF: {B9191F79-5613-4C76-AA2A-398534BB8999} (YAddBook Class) - http://us.dl1.yimg.com/download.yaho...tocomplete.cab
O16 - DPF: {F58E1CEF-A068-4C15-BA5E-587CAF3EE8C6} (MSN Chat Control 4.5) - http://chat.msn.com/bin/msnchat45.cab
O23 - Service: Symantec Event Manager (ccEvtMgr) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccEvtMgr.exe
O23 - Service: Symantec Network Proxy (ccProxy) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccProxy.exe
O23 - Service: Symantec Password Validation (ccPwdSvc) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccPwdSvc.exe
O23 - Service: Symantec Settings Manager (ccSetMgr) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccSetMgr.exe
O23 - Service: ISSvc (ISSVC) - Symantec Corporation - C:\Program Files\Norton Internet Security\ISSVC.exe
O23 - Service: LexBce Server (LexBceS) - Lexmark International, Inc. - C:\WINDOWS\system32\LEXBCES.EXE
O23 - Service: Norton AntiVirus Auto-Protect Service (navapsvc) - Symantec Corporation - C:\Program Files\Norton Internet Security\Norton AntiVirus\navapsvc.exe
O23 - Service: SAVScan - Symantec Corporation - C:\Program Files\Norton Internet Security\Norton AntiVirus\SAVScan.exe
O23 - Service: ScriptBlocking Service (SBService) - Symantec Corporation - C:\PROGRA~1\COMMON~1\SYMANT~1\SCRIPT~1\SBServ.exe
O23 - Service: Symantec Network Drivers Service (SNDSrvc) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\SNDSrvc.exe
O23 - Service: Symantec SPBBCSvc (SPBBCSvc) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\SPBBC\SPBBCSvc.exe
O23 - Service: Symantec Core LC - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\CCPD-LC\symlcsvc.exe
O23 - Service: VNC Server (winvnc) - Unknown owner - C:\Program Files\RealVNC\WinVNC\WinVNC.exe" -service (file missing)

Hiya,
If you still require help, could you post your entire log here and I'll take a look. Sorry about the response time.