Blank Desktop, Userinit.exe Error

Hi, I would apprecitate any help or advice on the following issue.

When I log onto Windows (2000 Pro), I get a message saying:
Userinit.exe - Application Error. The Instruction at "0x0040b961" referenced memory at 0x0000000010. The memory could not be read. After I click Ok, the Desktop is blank with none of my icons etc. visible.. However, if I open Task Manager and click on a folder and then explore, everything reappears, and I get a similar Application Error message, this time for Ctfmon.exe.

Also My internet connection is not working, and although my Modem is installed, The Internet Setup Wizard keeps saying that a modem needs to be installed. I have tried uninstalling and reinstalling. When I try to set up a new Internet connection, the Wizard closes automatically.

I would greatly appreciate any help on this issue, as it is quite frustrating!!

My Hijackthis log file is as Follows:

Logfile of HijackThis v1.99.0
Scan saved at 19:41:50, on 10/09/2005
Platform: Windows 2000 SP1 (WinNT 5.00.2195)
MSIE: Internet Explorer v6.00 SP1 (6.00.2800.1106)

Running processes:
C:\WINNT\System32\smss.exe
C:\WINNT\system32\winlogon.exe
C:\WINNT\system32\services.exe
C:\WINNT\system32\lsass.exe
C:\WINNT\system32\svchost.exe
C:\WINNT\system32\svchost.exe
C:\WINNT\system32\spoolsv.exe
C:\WINNT\system32\regsvc.exe
C:\WINNT\system32\MSTask.exe
C:\WINNT\Explorer.exe
C:\Program Files\QuickTime\qttask.exe
C:\Program Files\Winamp3\winampa.exe
C:\Program Files\Kodak\Kodak EasyShare software\bin\EasyShare.exe
C:\Program Files\SpywareGuard\sgmain.exe
C:\Program Files\Freecom Personal Media Suite\FCPMS.exe
C:\Program Files\SpywareGuard\sgbhp.exe
C:\Documents and Settings\greyhound\Desktop\Protection Software\HiJackThis\HijackThis.exe
C:\WINNT\system32\notepad.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://home.iol.ie
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://home.iol.ie/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://home.iol.ie
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = http://home.iol.ie
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Local Page =
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyOverride = ;<local>
F2 - REG:system.ini: UserInit=C:\WINNT\system32\userinit.exe
O1 - Hosts file is located at: C:\WINNT\System32\drivers\etc\hosts
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [Synchronization Manager] mobsync.exe /logon
O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE NvQTwk,NvCplDaemon initialize
O4 - HKLM\..\Run: [WinampAgent] "C:\Program Files\Winamp3\winampa.exe"
O4 - HKLM\..\RunServices: [SchedulingAgent] mstask.exe
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINNT\system\ctfmon.exe
O4 - Startup: SpywareGuard.lnk = C:\Program Files\SpywareGuard\sgmain.exe
O4 - Startup: Freecom Personal Media Suite.lnk = C:\Program Files\Freecom Personal Media Suite\FCPMS.exe
O4 - Global Startup: Kodak EasyShare software.lnk = C:\Program Files\Kodak\Kodak EasyShare software\bin\EasyShare.exe
O23 - Service: Logical Disk Manager Administrative Service - VERITAS Software Corp. - C:\WINNT\System32\dmadmin.exe