Hi, I think my browser got hijacked, because sometimes the Iexplorer.exe uses nearly 100% of the CPU.
So I used the Hijack this, and here's the log:

Logfile of HijackThis v1.97.7
Scan saved at 14:50:32, on 22-06-2004
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:\Programas\TGTSoft\StyleXP\StyleXPService.exe
C:\Programas\Ficheiros comuns\Symantec Shared\ccSetMgr.exe
C:\Programas\Ficheiros comuns\Symantec Shared\ccEvtMgr.exe
C:\WINDOWS\system32\spoolsv.exe
C:\WINDOWS\SYSTEM32\Ati2evxx.exe
C:\Aston\aston.exe
C:\Aston\XP\internat.exe
C:\Programas\Creative\SBAudigy2\Surround Mixer\CTSysVol.exe
C:\Programas\Creative\SBAudigy2\DVDAudio\CTDVDDet.EXE
C:\WINDOWS\System32\CTHELPER.EXE
C:\Programas\ATI Technologies\ATI Control Panel\atiptaxx.exe
C:\WINDOWS\System32\spool\drivers\w32x86\3\hpztsb08.exe
C:\Programas\Hewlett-Packard\HP Software Update\HPWuSchd.exe
C:\Programas\Hewlett-Packard\Digital Imaging\bin\hpotdd01.exe
C:\Arquivos de programas\MUSICMATCH\MUSICMATCH Jukebox\mm_tray.exe
C:\Programas\Logitech\iTouch\iTouch.exe
C:\WINDOWS\System32\taskswitch.exe
C:\WINDOWS\System32\fast.exe
C:\Programas\QuickTime\qttask.exe
C:\Arquivos de programas\MUSICMATCH\MUSICMATCH Jukebox\mmtask.exe
C:\Programas\Ficheiros comuns\Symantec Shared\ccApp.exe
C:\PROGRA~1\ADMINV~1\TypeWinDent.exe
C:\Programas\Winamp\winampa.exe
C:\Programas\SlySoft\CloneCD\CloneCDTray.exe
C:\Program Files\ASUS\Probe\AsusProb.exe
C:\Programas\Messenger Plus! 3\MsgPlus.exe
C:\Programas\Netcount\Netcount.exe
C:\Programas\Rainlendar\Rainlendar.exe
C:\Programas\Logitech\MouseWare\system\em_exec.exe
C:\Programas\InterVideo\Common\Bin\WinCinemaMgr.exe
C:\Programas\Norton AntiVirus\navapsvc.exe
C:\Programas\Norton AntiVirus\AdvTools\NPROTECT.EXE
C:\WINDOWS\System32\svchost.exe
C:\Programas\Ficheiros comuns\Symantec Shared\CCPD-LC\symlcsvc.exe
C:\WINDOWS\System32\MsPMSPSv.exe
C:\WINDOWS\System32\Fast.exe
C:\PROGRA~1\MOZILL~1\firefox.exe
C:\Programas\Internet Explorer\IEXPLORE.EXE
C:\Programas\WinRAR\WinRAR.exe
C:\DOCUME~1\FRANCI~1\DEFINI~1\Temp\Rar$EX00.797\HijackThis.exe
C:\Programas\Messenger\msmsgs.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://g.msn.com/0SEENUS/SAOS01
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://mysearchnow.com/passthrough/i...nonce.msn.com/
R1 - HKCU\Software\Microsoft\Internet Explorer\Search,SearchAssistant = http://mysearchnow.com/searchbar.html
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Bar = http://mysearchnow.com/searchbar.html
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Hiperligações
F0 - system.ini: Shell=C:\Aston\aston.exe ,svchost.exe
O1 - Hosts: 69.1.67.70 btuga.com www.btuga.com
O2 - BHO: (no name) - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Programas\Adobe\Acrobat 6.0\Reader\ActiveX\AcroIEHelper.dll
O2 - BHO: (no name) - {53707962-6F74-2D53-2644-206D7942484F} - C:\Programas\Spybot - Search & Destroy\SDHelper.dll
O2 - BHO: NAV Helper - {BDF3E430-B101-42AD-A544-FADC6B084872} - C:\Programas\Norton AntiVirus\NavShExt.dll
O2 - BHO: (no name) - {E06DE18D-7530-977B-A974-82B8E32C6724} - C:\PROGRA~1\gridheck\HTM PURE.dll
O3 - Toolbar: &Rádio - {8E718888-423F-11D2-876E-00A0C9082467} - C:\WINDOWS\System32\msdxm.ocx
O3 - Toolbar: Norton AntiVirus - {42CDD1BF-3FFB-4238-8AD1-7859DF00B1D6} - C:\Programas\Norton AntiVirus\NavShExt.dll
O3 - Toolbar: Barra de Ferramentas MSN - {BDAD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Programas\MSN Toolbar\01.01.1629.0\pt-br\msntb.dll
O3 - Toolbar: mags manager - {ECFF9B8F-84C7-09D2-F1C2-1F4DE7DD2099} - C:\PROGRA~1\gridheck\HTM PURE.dll
O4 - HKLM\..\Run: [CTSysVol] C:\Programas\Creative\SBAudigy2\Surround Mixer\CTSysVol.exe
O4 - HKLM\..\Run: [CTDVDDet] C:\Programas\Creative\SBAudigy2\DVDAudio\CTDVDDet.EXE
O4 - HKLM\..\Run: [CTHelper] CTHELPER.EXE
O4 - HKLM\..\Run: [AsioReg] REGSVR32.EXE /S CTASIO.DLL
O4 - HKLM\..\Run: [SBDrvDet] C:\Programas\Creative\SB Drive Det\SBDrvDet.exe /r
O4 - HKLM\..\Run: [UpdReg] C:\WINDOWS\UpdReg.EXE
O4 - HKLM\..\Run: [ATIPTA] C:\Programas\ATI Technologies\ATI Control Panel\atiptaxx.exe
O4 - HKLM\..\Run: [HPDJ Taskbar Utility] C:\WINDOWS\System32\spool\drivers\w32x86\3\hpztsb08.exe
O4 - HKLM\..\Run: [HP Software Update] C:\Programas\Hewlett-Packard\HP Software Update\HPWuSchd.exe
O4 - HKLM\..\Run: [DeviceDiscovery] C:\Programas\Hewlett-Packard\Digital Imaging\bin\hpotdd01.exe
O4 - HKLM\..\Run: [MMTray] C:\Arquivos de programas\MUSICMATCH\MUSICMATCH Jukebox\mm_tray.exe
O4 - HKLM\..\Run: [zBrowser Launcher] C:\Programas\Logitech\iTouch\iTouch.exe
O4 - HKLM\..\Run: [StorageGuard] "C:\Programas\VERITAS Software\Update Manager\sgtray.exe" /r
O4 - HKLM\..\Run: [PtiuPbmd] Rundll32.exe ptipbm.dll,SetWriteBack
O4 - HKLM\..\Run: [NeroCheck] C:\WINDOWS\system32\NeroCheck.exe
O4 - HKLM\..\Run: [BackgroundSwitcher] C:\WINDOWS\System32\bgswitch.exe
O4 - HKLM\..\Run: [CoolSwitch] C:\WINDOWS\System32\taskswitch.exe
O4 - HKLM\..\Run: [FastUser] C:\WINDOWS\System32\fast.exe
O4 - HKLM\..\Run: [QuickTime Task] "C:\Programas\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [mmtask] C:\Arquivos de programas\MUSICMATCH\MUSICMATCH Jukebox\mmtask.exe
O4 - HKLM\..\Run: [Logitech Utility] Logi_MwX.Exe
O4 - HKLM\..\Run: [ccApp] "C:\Programas\Ficheiros comuns\Symantec Shared\ccApp.exe"
O4 - HKLM\..\Run: [NAV CfgWiz] C:\Programas\Ficheiros comuns\Symantec Shared\CfgWiz.exe /GUID NAV /CMDLINE "REBOOT"
O4 - HKLM\..\Run: [Advanced Tools Check] C:\PROGRA~1\NORTON~1\AdvTools\ADVCHK.EXE
O4 - HKLM\..\Run: [book proc] C:\PROGRA~1\ADMINV~1\TypeWinDent.exe
O4 - HKLM\..\Run: [AutoUpdater] "C:\Program Files\AutoUpdate\AutoUpdate.exe"
O4 - HKLM\..\Run: [WinampAgent] C:\Programas\Winamp\winampa.exe
O4 - HKLM\..\Run: [ElbyCheckElbyCDFL] "C:\Program Files\Elaborate Bytes\CloneCD\ElbyCheck.exe" /L ElbyCDFL
O4 - HKLM\..\Run: [CloneCDTray] "C:\Programas\SlySoft\CloneCD\CloneCDTray.exe" /s
O4 - HKLM\..\Run: [ASUS Probe] C:\Program Files\ASUS\Probe\AsusProb.exe
O4 - HKLM\..\Run: [Windows SA] C:\Program Files\WindowsSA\omniscient.exe
O4 - HKLM\..\Run: [MessengerPlus3] "C:\Programas\Messenger Plus! 3\MsgPlus.exe"
O4 - HKCU\..\Run: [STYLEXP] C:\Programas\TGTSoft\StyleXP\StyleXP.exe -Hide
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\System32\ctfmon.exe
O4 - HKCU\..\Run: [MessengerPlus3] "C:\Programas\Messenger Plus! 3\MsgPlus.exe" /WinStart
O4 - Startup: Amsn.lnk = C:\Programas\Amsn\amsn.exe
O4 - Startup: Netcount.lnk = ?
O4 - Startup: PowerReg Scheduler.exe
O4 - Startup: Rainlendar.lnk = C:\Programas\Rainlendar\Rainlendar.exe
O4 - Global Startup: Adobe Gamma Loader.lnk = C:\Programas\Ficheiros comuns\Adobe\Calibration\Adobe Gamma Loader.exe
O4 - Global Startup: GetRight - Tray Icon.lnk = C:\Programas\GetRight\getright.exe
O4 - Global Startup: InterVideo WinCinema Manager.lnk = C:\Programas\InterVideo\Common\Bin\WinCinemaMgr.exe
O4 - Global Startup: Microsoft Office.lnk = C:\Programas\Microsoft Office\Office10\OSA.EXE
O8 - Extra context menu item: Download with GetRight - C:\Programas\GetRight\GRdownload.htm
O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:\PROGRA~1\MICROS~2\Office10\EXCEL.EXE/3000
O8 - Extra context menu item: Open with GetRight Browser - C:\Programas\GetRight\GRbrowse.htm
O9 - Extra button: Real.com (HKLM)
O9 - Extra button: Messenger (HKLM)
O9 - Extra 'Tools' menuitem: Windows Messenger (HKLM)
O12 - Plugin for .spop: C:\Programas\Internet Explorer\Plugins\NPDocBox.dll
O16 - DPF: {00B71CFB-6864-4346-A978-C0A14556272C} (Checkers Class) - http://messenger.zone.msn.com/binary/msgrchkr.cab
O16 - DPF: {54B52E52-8000-4413-BD67-FC7FE24B59F2} (EARTPatchX Class) - http://www.ea.com/downloads/rtpatch/EARTPX.cab
O16 - DPF: {8E0D4DE5-3180-4024-A327-4DFAD1796A8D} (MessengerStatsClient Class) - http://messenger.zone.msn.com/binary...tatsClient.cab
O16 - DPF: {9F1C11AA-197B-4942-BA54-47A8489BB47F} (Update Class) - http://v4.windowsupdate.microsoft.co...847.3377893519
O16 - DPF: {A8658086-E6AC-4957-BC8E-7D54A7E8A78E} (SassCln Object) - http://www.microsoft.com/security/controls/SassCln.CAB
O16 - DPF: {D27CDB6E-AE6D-11CF-96B8-444553540000} (Shockwave Flash Object) - http://download.macromedia.com/pub/s...sh/swflash.cab

Please Help

Reboot into safe mode following the instructions here & Unzip HJT into it's own permanent folder before doing anything in order for it to create backups. (Not a temporary folder or directly on the desktop & not directly on your hard drive). Close all (browser) windows & rescan with hijackthis. When the scan is finished place a check in the box to the left of the following entries & click 'fix checked' :

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://mysearchnow.com/passthrough/...unonce.msn.com/
R1 - HKCU\Software\Microsoft\Internet Explorer\Search,SearchAssistant = http://mysearchnow.com/searchbar.html
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Bar = http://mysearchnow.com/searchbar.html

F0 - system.ini: Shell=C:\Aston\aston.exe ,svchost.exe

O1 - Hosts: 69.1.67.70 btuga.com www.btuga.com

O2 - BHO: (no name) - {E06DE18D-7530-977B-A974-82B8E32C6724} - C:\PROGRA~1\gridheck\HTM PURE.dll

O3 - Toolbar: mags manager - {ECFF9B8F-84C7-09D2-F1C2-1F4DE7DD2099} - C:\PROGRA~1\gridheck\HTM PURE.dll

O4 - HKLM\..\Run: [book proc] C:\PROGRA~1\ADMINV~1\TypeWinDent.exe
O4 - HKLM\..\Run: [AutoUpdater] "C:\Program Files\AutoUpdate\AutoUpdate.exe"
O4 - HKLM\..\Run: [Windows SA] C:\Program Files\WindowsSA\omniscient.exe

Delete the following manually:

C:\PROGRA~1\gridheck< folder
C:\PROGRA~1\ADMINV~1< folder
C:\Program Files\AutoUpdate< folder
C:\Program Files\WindowsSA< folder

Reboot normally after doing the above then post a fresh log plz.