what is a proxy overide?

Logfile of HijackThis v1.98.2
Scan saved at 6:48:19 PM, on 9/4/2004
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\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\Common Files\Dell\EUSW\Support.exe
C:\PROGRA~1\SYMANT~1\SYMANT~1\vptray.exe
C:\Program Files\Common Files\Real\Update_OB\realsched.exe
C:\Program Files\Synaptics\SynTP\SynTPLpr.exe
C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
C:\WINDOWS\System32\spool\drivers\w32x86\3\hpztsb05.exe
C:\WINDOWS\System32\hkcmd.exe
C:\Program Files\Roxio\Easy CD Creator 5\DirectCD\DirectCD.exe
C:\Program Files\Messenger\msmsgs.exe
C:\Program Files\EarthLink TotalAccess\TaskPanl.exe
C:\Program Files\FinePixViewer\QuickDCF.exe
C:\Program Files\Dell TrueMobile 1150\Client Manager\CmDEL.exe
C:\Program Files\Symantec_Client_Security\Symantec AntiVirus\DefWatch.exe
C:\Program Files\Symantec_Client_Security\Symantec AntiVirus\Rtvscan.exe
C:\Program Files\earthlinkim\aim.exe
C:\Program Files\LIUtilities\WinTasks\wintasks.exe
C:\hijack\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://start.earthlink.net
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://www.earthlink.net/partner/more/msie/button/search.html
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://www.earthlink.net/partner/more/msie/button/search.html
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = http://www.earthlink.net/partner/more/msie/button/search.html
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://www.dellnet.com
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Bar = http://red.clientapps.yahoo.com/customize/ie/defaults/sb/ymsgr/*http://www.yahoo.com/ext/search/search.html
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = http://red.clientapps.yahoo.com/customize/ie/defaults/stp/ymsgr*http://my.yahoo.com
R1 - HKCU\Software\Microsoft\Internet Explorer\SearchURL,(Default) = http://red.clientapps.yahoo.com/customize/ie/defaults/su/ymsgr/*http://www.yahoo.com
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyOverride = 127.0.0.1;http://localhost
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName =
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 6.0\Reader\ActiveX\AcroIEHelper.dll
O2 - BHO: PnIEBrowserHelperObj Class - {4B5F2E08-6F39-479a-B547-B2026E4C7EDF} - C:\Program Files\EarthLink TotalAccess\PnEL.dll
O3 - Toolbar: &Radio - {8E718888-423F-11D2-876E-00A0C9082467} - C:\WINDOWS\System32\msdxm.ocx
O3 - Toolbar: Pop-Up Blocker - {D7F30B62-8269-41AF-9539-B2697FA7D77E} - C:\Program Files\EarthLink TotalAccess\PnEL.dll
O4 - HKLM\..\Run: [DwlClient] C:\Program Files\Common Files\Dell\EUSW\Support.exe
O4 - HKLM\..\Run: [vptray] C:\PROGRA~1\SYMANT~1\SYMANT~1\vptray.exe
O4 - HKLM\..\Run: [TkBellExe] "C:\Program Files\Common Files\Real\Update_OB\realsched.exe" -osboot
O4 - HKLM\..\Run: [SynTPLpr] C:\Program Files\Synaptics\SynTP\SynTPLpr.exe
O4 - HKLM\..\Run: [SynTPEnh] C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
O4 - HKLM\..\Run: [IgfxTray] C:\WINDOWS\System32\igfxtray.exe
O4 - HKLM\..\Run: [HPDJ Taskbar Utility] C:\WINDOWS\System32\spool\drivers\w32x86\3\hpztsb05.exe
O4 - HKLM\..\Run: [HotKeysCmds] C:\WINDOWS\System32\hkcmd.exe
O4 - HKLM\..\Run: [AdaptecDirectCD] "C:\Program Files\Roxio\Easy CD Creator 5\DirectCD\DirectCD.exe"
O4 - HKCU\..\Run: [MSMSGS] "C:\Program Files\Messenger\msmsgs.exe" /background
O4 - HKCU\..\Run: [Yahoo! Pager] C:\Program Files\Yahoo!\Messenger\ypager.exe -quiet
O4 - HKCU\..\Run: [E6TaskPanel] "C:\Program Files\EarthLink TotalAccess\TaskPanl.exe" -winstart
O4 - Global Startup: Exif Launcher.lnk = ?
O4 - Global Startup: Microsoft Office.lnk = C:\Program Files\Microsoft Office\Office10\OSA.EXE
O4 - Global Startup: TrueMobile 1150 Client Manager.lnk = C:\Program Files\Dell TrueMobile 1150\Client Manager\CmDEL.exe
O6 - HKCU\Software\Policies\Microsoft\Internet Explorer\Control Panel present
O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:\PROGRA~1\MICROS~2\Office10\EXCEL.EXE/3000
O9 - Extra button: Instant Messenger (SM) - {AC9E2541-2814-11d5-BC6D-00B0D0A1DE45} - C:\Program Files\earthlinkim\aim.exe
O9 - Extra button: Real.com - {CD67F990-D8E9-11d2-98FE-00C0F0318AFE} - C:\WINDOWS\System32\Shdocvw.dll
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\MSMSGS.EXE
O9 - Extra 'Tools' menuitem: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\MSMSGS.EXE
O12 - Plugin for .mov: C:\Program Files\Internet Explorer\PLUGINS\npqtplugin.dll
O16 - DPF: {6414512B-B978-451D-A0D8-FCFDF33E833C} (WUWebControl Class) - http://v5.windowsupdate.microsoft.com/v5consumer/V5Controls/en/x86/client/wuweb_site.cab?1093308777255
O16 - DPF: {C3DFA998-A486-11D4-AA25-00C04F72DAEB} (MSN Photo Upload Tool) - http://sc.groups.msn.com/controls/PhotoUC/MsnPUpld.cab