Download HijackThis selfextracting zip version from here. Once downloaded, double click on the file & it will install into it's own, permanent folder.
Start HJT & press the "Do a system scan and save a log file" button. When the scan is finished a window will pop up giving you the option of where to save it. Save it to desktop where it is easy to access. Open the log file and copy the entire contents of the file & paste it into the body of your post. DO NOT FIX ANYTHING YET. Most of what is there is necessary for the running of your system.

If you do not get the self-extracting version, please make sure that hijackthis is in a permanent folder before scanning with it.

Thanks for reply. Here's the log:

Logfile of HijackThis v1.99.1
Scan saved at 11:38:18 AM, on 6/8/2005
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\system32\spoolsv.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\Mixer.exe
C:\Program Files\ICQLite\ICQLite.exe
C:\WINDOWS\SOUNDMAN.EXE
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Messenger\msmsgs.exe
C:\Program Files\Adobe\Acrobat 5.0\Distillr\AcroTray.exe
C:\PROGRA~1\Grisoft\AVGFRE~1\avgupsvc.exe
C:\Program Files\Common Files\Microsoft Shared\VS7Debug\mdm.exe
C:\WINDOWS\System32\nvsvc32.exe
C:\Program Files\MSN Messenger\msnmsgr.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Adobe\Acrobat 5.0\Acrobat\Acrobat.exe
C:\PROGRA~1\Grisoft\AVGFRE~1\avgamsvr.exe
C:\PROGRA~1\Grisoft\AVGFRE~1\avgcc.exe
C:\PROGRA~1\Grisoft\AVGFRE~1\avgemc.exe
C:\Program Files\Netscape\Netscape\Netscp.exe
C:\Documents and Settings\Denn1s\Desktop\Hijack this\HijackThis.exe

O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 5.0\Acrobat\ActiveX\AcroIEHelper.ocx
O4 - HKLM\..\Run: [C-Media Mixer] Mixer.exe /startup
O4 - HKLM\..\Run: [NeroCheck] C:\WINDOWS\System32\\NeroCheck.exe
O4 - HKLM\..\Run: [ICQ Lite] C:\Program Files\ICQLite\ICQLite.exe -minimize
O4 - HKLM\..\Run: [SoundMan] SOUNDMAN.EXE
O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE C:\WINDOWS\System32\NvCpl.dll,NvStartup
O4 - HKLM\..\Run: [nwiz] nwiz.exe /install
O4 - HKLM\..\Run: [NvMediaCenter] RUNDLL32.EXE C:\WINDOWS\System32\NvMcTray.dll,NvTaskbarInit
O4 - HKLM\..\Run: [AVG7_CC] C:\PROGRA~1\Grisoft\AVGFRE~1\avgcc.exe /STARTUP
O4 - HKLM\..\Run: [AVG7_EMC] C:\PROGRA~1\Grisoft\AVGFRE~1\avgemc.exe
O4 - HKCU\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [MsnMsgr] "C:\Program Files\MSN Messenger\MsnMsgr.Exe" /background
O4 - HKCU\..\Run: [MSMSGS] "C:\Program Files\Messenger\msmsgs.exe" /background
O4 - HKCU\..\RunOnce: [ICQ Lite] C:\Program Files\ICQLite\ICQLite.exe -trayboot
O4 - Global Startup: Acrobat Assistant.lnk = C:\Program Files\Adobe\Acrobat 5.0\Distillr\AcroTray.exe
O4 - Global Startup: Adobe Gamma Loader.lnk = C:\Program Files\Common Files\Adobe\Calibration\Adobe Gamma Loader.exe
O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:\PROGRA~1\MICROS~2\Office10\EXCEL.EXE/3000
O9 - Extra button: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~2\OFFICE11\REFIEBAR.DLL
O9 - Extra button: ICQ Lite - {B863453A-26C3-4e1f-A54D-A2CD196348E9} - C:\Program Files\ICQLite\ICQLite.exe
O9 - Extra 'Tools' menuitem: ICQ Lite - {B863453A-26C3-4e1f-A54D-A2CD196348E9} - C:\Program Files\ICQLite\ICQLite.exe
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
O18 - Protocol: ms-help - {314111C7-A502-11D2-BBCA-00C04F8EC294} - C:\Program Files\Common Files\Microsoft Shared\Help\hxds.dll
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: NVIDIA Display Driver Service (NVSvc) - NVIDIA Corporation - C:\WINDOWS\System32\nvsvc32.exe

There is nothing showing in that log. Did you fix anything with it? Try rebooting, rescan with hijackthis and post that log please.

Download the Hoster.
Run it and press "Restore Original Hosts" and press "OK". Exit Program.
Note that if you have a custom host file, this will remove it. You can edit the host file with this program too.