Hola de nuevo! Gracias por la ayuda. Hice todo lo que me dijeron pero no consegui encontrar ningun archivo C:\WINDOWS\SYSTEM\MACG.DLL y
C:\PROGRAM FILES\WINDOWS ADCONTROL\WINADCTL.EXE y en el administrador de tareas no encontre nada referente a WINADCTL.EXE. De todas formas parece que el problema esta resolvido, pues ya consegui acceder al hotmail y no me han aparecido mas ventanas del tipo "warning". Aqui esta mi nuevo log por si quedo algo para resolver:

Logfile of HijackThis v1.99.1
Scan saved at 15:07:32, on 04-03-2005
Platform: Windows 98 SE (Win9x 4.10.2222A)
MSIE: Internet Explorer v6.00 SP1 (6.00.2800.1106)

Running processes:
C:\WINDOWS\SYSTEM\KERNEL32.DLL
C:\WINDOWS\SYSTEM\MSGSRV32.EXE
C:\WINDOWS\SYSTEM\MPREXE.EXE
C:\WINDOWS\SYSTEM\MSTASK.EXE
C:\PROGRAM FILES\NORTON SYSTEMWORKS\NORTON UTILITIES\NPROTECT.EXE
C:\PROGRAM FILES\COMMON FILES\SYMANTEC SHARED\SYMTRAY.EXE
C:\WINDOWS\SYSTEM\mmtask.tsk
C:\WINDOWS\EXPLORER.EXE
C:\WINDOWS\TASKMON.EXE
C:\WINDOWS\SYSTEM\SYSTRAY.EXE
C:\PROGRAM FILES\ADAPTEC\EASY CD CREATOR 5\DIRECTCD\DIRECTCD.EXE
C:\WINDOWS\SYSTEM\STIMON.EXE
C:\WINDOWS\LOADQM.EXE
C:\WINDOWS\SYSTEM\IRMON.EXE
C:\PROGRAM FILES\WINAMP\WINAMPA.EXE
C:\PROGRAM FILES\NORTON SYSTEMWORKS\NORTON ANTIVIRUS\NAVAPW32.EXE
C:\WINDOWS\SYSTEM\SPOOL32.EXE
C:\WINDOWS\SYSTEM\SRSTRAY.EXE
C:\PROGRAM FILES\COMMON FILES\REAL\UPDATE_OB\REALSCHED.EXE
C:\WINDOWS\SYSTEM\MSTINIT.EXE
C:\PROGRAM FILES\SPYBOT - SEARCH & DESTROY\TEATIMER.EXE
C:\WINDOWS\SYSTEM\LEXBCES.EXE
C:\WINDOWS\SYSTEM\WMIEXE.EXE
C:\WINDOWS\SYSTEM\RPCSS.EXE
C:\WINDOWS\SYSTEM\LEXPPS.EXE
C:\PROGRAM FILES\INTERNET EXPLORER\IEXPLORE.EXE
C:\WINDOWS\SYSTEM\DDHELP.EXE
C:\WINDOWS\SYSTEM\PSTORES.EXE
C:\MY DOCUMENTS\MIS ARCHIVOS RECIBIDOS\HIJACKTHIS\HIJACKTHIS.EXE

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = about:blank
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.hotmail.com/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = about:blank
R1 - HKCU\Software\Microsoft\Internet Explorer\Search,SearchAssistant = about:blank
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant = about:blank
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,HomeOldSP = about:blank
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,HomeOldSP = about:blank
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\PROGRAM FILES\ADOBE\ACROBAT 5.0\READER\ACTIVEX\ACROIEHELPER.OCX
O2 - BHO: NAV Helper - {BDF3E430-B101-42AD-A544-FADC6B084872} - C:\Program Files\Norton SystemWorks\Norton AntiVirus\NavShExt.dll
O2 - BHO: (no name) - {53707962-6F74-2D53-2644-206D7942484F} - C:\PROGRA~1\SPYBOT~1\SDHELPER.DLL
O3 - Toolbar: Norton AntiVirus - {42CDD1BF-3FFB-4238-8AD1-7859DF00B1D6} - C:\Program Files\Norton SystemWorks\Norton AntiVirus\NavShExt.dll
O3 - Toolbar: &Radio - {8E718888-423F-11D2-876E-00A0C9082467} - C:\WINDOWS\SYSTEM\MSDXM.OCX
O4 - HKLM\..\Run: [ScanRegistry] C:\WINDOWS\scanregw.exe /autorun
O4 - HKLM\..\Run: [TaskMonitor] C:\WINDOWS\taskmon.exe
O4 - HKLM\..\Run: [SystemTray] SysTray.Exe
O4 - HKLM\..\Run: [bpcpost.exe] C:\WINDOWS\SYSTEM\bpcpost.exe
O4 - HKLM\..\Run: [LexStart] Lexstart.exe
O4 - HKLM\..\Run: [LexmarkPrinTray] PrinTray.exe
O4 - HKLM\..\Run: [AdaptecDirectCD] "C:\Program Files\Adaptec\Easy CD Creator 5\DirectCD\DirectCD.exe"
O4 - HKLM\..\Run: [StillImageMonitor] C:\WINDOWS\SYSTEM\STIMON.EXE
O4 - HKLM\..\Run: [LoadQM] loadqm.exe
O4 - HKLM\..\Run: [IrMon] IrMon.exe
O4 - HKLM\..\Run: [WinampAgent] C:\Program Files\Winamp\winampa.exe
O4 - HKLM\..\Run: [NAV Agent] C:\PROGRA~1\NORTON~1\NORTON~1\NAVAPW32.EXE
O4 - HKLM\..\Run: [NPROTECT] C:\Program Files\Norton SystemWorks\Norton Utilities\NPROTECT.EXE
O4 - HKLM\..\Run: [Symantec NetDriver Monitor] C:\PROGRA~1\SYMANTEC\LIVEUP~1\SNDMON.EXE
O4 - HKLM\..\Run: [SRS Applet] SrsTray.Exe
O4 - HKLM\..\Run: [TkBellExe] "C:\Program Files\Common Files\Real\Update_OB\realsched.exe" -osboot
O4 - HKLM\..\Run: [LoadPowerProfile] Rundll32.exe powrprof.dll,LoadCurrentPwrScheme
O4 - HKLM\..\RunServices: [SchedulingAgent] mstask.exe
O4 - HKLM\..\RunServices: [ScriptBlocking] "C:\Program Files\Common Files\Symantec Shared\Script Blocking\SBServ.exe" -reg
O4 - HKLM\..\RunServices: [NPROTECT] C:\Program Files\Norton SystemWorks\Norton Utilities\NPROTECT.EXE
O4 - HKLM\..\RunServices: [SymTray - Norton SystemWorks] C:\Program Files\Common Files\Symantec Shared\SymTray.exe "Norton SystemWorks"
O4 - HKLM\..\RunServices: [LoadPowerProfile] Rundll32.exe powrprof.dll,LoadCurrentPwrScheme
O4 - HKCU\..\Run: [SpybotSD TeaTimer] C:\Program Files\Spybot - Search & Destroy\TeaTimer.exe
O4 - Startup: POWERR~1.EXE
O4 - Startup: HotSync Manager.lnk = C:\Program Files\Palm\HOTSYNC.EXE
O4 - User Startup: POWERR~1.EXE
O4 - User Startup: HotSync Manager.lnk = C:\Program Files\Palm\HOTSYNC.EXE
O6 - HKCU\Software\Policies\Microsoft\Internet Explorer\Control Panel present
O6 - HKLM\Software\Policies\Microsoft\Internet Explorer\Control Panel present
O12 - Plugin for .mp3: C:\PROGRA~1\INTERN~1\PLUGINS\npqtplugin3.dll
O12 - Plugin for .pdf: C:\PROGRA~1\INTERN~1\PLUGINS\nppdf32.dll
O12 - Plugin for .mid: C:\PROGRA~1\INTERN~1\PLUGINS\npqtplugin2.dll
O12 - Plugin for .mov: C:\PROGRA~1\INTERN~1\PLUGINS\npqtplugin.dll
O12 - Plugin for .mpg: C:\PROGRA~1\INTERN~1\PLUGINS\npqtplugin3.dll
O12 - Plugin for .mpeg: C:\PROGRA~1\INTERN~1\PLUGINS\npqtplugin3.dll
O16 - DPF: {56336BCB-3D8A-11D6-A00B-0050DA18DE71} (RdxIE Class) - http://software-dl.real.com/15efd8c6...dxIE601_es.cab
O16 - DPF: {8E0D4DE5-3180-4024-A327-4DFAD1796A8D} (MessengerStatsClient Class) - http://messenger.zone.msn.com/binary...t.cab31267.cab
O16 - DPF: {00B71CFB-6864-4346-A978-C0A14556272C} (Checkers Class) - http://messenger.zone.msn.com/binary...r.cab31267.cab
O16 - DPF: {B38870E4-7ECB-40DA-8C6A-595F0A5519FF} (MsnMessengerSetupDownloadControl Class) - http://messenger.msn.com/download/Ms...Downloader.cab
O16 - DPF: {10003000-1000-0000-1000-000000000000} - ms-its:mhtml:file://C:\foo.mht!http://bin.wordsx.cc/4WYtQuMsUL2trEs...::/on-line.exe

Me alegra de haber personas como ustedes dispuestos a ayudar a usuarios como yo. GRACIAS