System running slowly and loudly

My system is Windows XP Home Edition Version 2002, Service Pack 3. My computer is Intel® Pentium ® 4CPU 2.40GHz 2-39 GHz. 512 MB of RAM. I use Firefox. My computer is very slow to load and I thought it was because of Avast! running at startup.
Then my D-drive stopped working; if I try to use it I get an internal error and everything shuts down.
I tried to uninstall my Adaware thinking maybe it was a rogue program but I can't do that either. The Windows Installer screen says 'this feature you are trying to use is on a network resource that is unavailable' and then tells me to enter an alternate path.
I don't surf alot but I do use Facebook and play Farmtown there.
Now my system is in such a strain that I can hear it running very loudly. It's also knocking me offline when I try to load pages and I can hear it straining.
I don't know what to do and would like to see if it can be fixed before I try to buy another one.
Thank you in advance.



Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 1:24:44 PM, on 9/7/2009
Platform: Windows XP SP3 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.6000.16876)
Boot mode: Normal

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:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
C:\Program Files\Alwil Software\Avast4\ashServ.exe
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\Common Files\Apple\Mobile Device Support\bin\AppleMobileDeviceService.exe
C:\Program Files\Bonjour\mDNSResponder.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Java\jre6\bin\jqs.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe
C:\Program Files\Alwil Software\Avast4\ashWebSv.exe
C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Google\GoogleToolbarNotifier\GoogleToolbarNotifier.exe
C:\Program Files\SpywareGuard\sgmain.exe
C:\Program Files\SpywareGuard\sgbhp.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\Program Files\Trend Micro\HijackThis\HijackThis.exe

R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://go.microsoft.com/fwlink/?LinkId=69157
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://go.microsoft.com/fwlink/?LinkId=54896
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = http://go.microsoft.com/fwlink/?LinkId=54896
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyOverride = localhost;*.local
O2 - BHO: Adobe PDF Reader Link Helper - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 7.0\ActiveX\AcroIEHelper.dll
O2 - BHO: CitiUSBrowserHelper Class - {387EDF53-1CF2-4523-BC2F-13462651BE8C} - C:\WINDOWS\system32\BhoCitUS.dll
O2 - BHO: SpywareGuard Download Protection - {4A368E80-174F-4872-96B5-0B27DDD11DB2} - C:\Program Files\SpywareGuard\dlprotect.dll
O2 - BHO: Yahoo! IE Services Button - {5BAB4B5B-68BC-4B02-94D6-2FC0DE4A7897} - C:\Program Files\Yahoo!\Common\yiesrvc.dll
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - C:\Program Files\Google\Google Toolbar\GoogleToolbar.dll
O2 - BHO: Google Toolbar Notifier BHO - {AF69DE43-7D58-4638-B6FA-CE66B5AD205D} - C:\Program Files\Google\GoogleToolbarNotifier\5.1.1309.15642\swg.dll
O2 - BHO: Google Dictionary Compression sdch - {C84D72FE-E17D-4195-BB24-76C02E2E7C4E} - C:\Program Files\Google\Google Toolbar\Component\fastsearch_A8904FB862BD9564.dll
O2 - BHO: Java(tm) Plug-In 2 SSV Helper - {DBC80044-A445-435b-BC74-9C25C1C588A9} - C:\Program Files\Java\jre6\bin\jp2ssv.dll
O3 - Toolbar: Google Toolbar - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - C:\Program Files\Google\Google Toolbar\GoogleToolbar.dll
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [swg] C:\Program Files\Google\GoogleToolbarNotifier\GoogleToolbarNotifier.exe
O4 - Startup: SpywareGuard.lnk = C:\Program Files\SpywareGuard\sgmain.exe
O8 - Extra context menu item: &Yahoo! Search - file:///C:\Program Files\Yahoo!\Common/ycsrch.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: Yahoo! &Dictionary - file:///C:\Program Files\Yahoo!\Common/ycdict.htm
O8 - Extra context menu item: Yahoo! &Maps - file:///C:\Program Files\Yahoo!\Common/ycmap.htm
O8 - Extra context menu item: Yahoo! &SMS - file:///C:\Program Files\Yahoo!\Common/ycsms.htm
O9 - Extra button: Citi - {4C730913-3961-439b-83D5-F4E445520422} - C:\Program Files\Citi Virtual Account Numbers\CitiVAN.exe
O9 - Extra button: Yahoo! Services - {5BAB4B5B-68BC-4B02-94D6-2FC0DE4A7897} - C:\Program Files\Yahoo!\Common\yiesrvc.dll
O9 - Extra button: (no name) - {85d1f590-48f4-11d9-9669-0800200c9a66} - C:\WINDOWS\bdoscandel.exe
O9 - Extra 'Tools' menuitem: Uninstall BitDefender Online Scanner v8 - {85d1f590-48f4-11d9-9669-0800200c9a66} - C:\WINDOWS\bdoscandel.exe
O9 - Extra button: (no name) - {e2e2dd38-d088-4134-82b7-f2ba38496583} - C:\WINDOWS\Network Diagnostic\xpnetdiag.exe
O9 - Extra 'Tools' menuitem: @xpsp3res.dll,-20001 - {e2e2dd38-d088-4134-82b7-f2ba38496583} - C:\WINDOWS\Network Diagnostic\xpnetdiag.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
O16 - DPF: {30528230-99f7-4bb4-88d8-fa1d4f56a2ab} (YInstStarter Class) - C:\Program Files\Yahoo!\Common\yinsthelper.dll
O16 - DPF: {4F1E5B1A-2A80-42CA-8532-2D05CB959537} - http://gfx1.hotmail.com/mail/w2/pr02/resources/MSNPUpld.cab
O16 - DPF: {5D86DDB5-BDF9-441B-9E9E-D4730F4EE499} (BDSCANONLINE Control) - http://download.bitdefender.com/resources/scan8/oscan8.cab
O16 - DPF: {90C9629E-CD32-11D3-BBFB-00105A1F0D68} - http://72.32.179.44/filter/cameraviewer/isetup.cab
O18 - Filter: x-sdch - {B1759355-3EEC-4C1E-B0F1-B719FE26E377} - C:\Program Files\Google\Google Toolbar\Component\fastsearch_A8904FB862BD9564.dll
O23 - Service: Lavasoft Ad-Aware Service (aawservice) - Unknown owner - C:\Program Files\Lavasoft\Ad-Aware\aawservice.exe (file missing)
O23 - Service: Apple Mobile Device - Apple Inc. - C:\Program Files\Common Files\Apple\Mobile Device Support\bin\AppleMobileDeviceService.exe
O23 - Service: avast! iAVS4 Control Service (aswUpdSv) - ALWIL Software - C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
O23 - Service: avast! Antivirus - ALWIL Software - C:\Program Files\Alwil Software\Avast4\ashServ.exe
O23 - Service: avast! Mail Scanner - ALWIL Software - C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe
O23 - Service: avast! Web Scanner - ALWIL Software - C:\Program Files\Alwil Software\Avast4\ashWebSv.exe
O23 - Service: Bonjour Service - Apple Inc. - C:\Program Files\Bonjour\mDNSResponder.exe
O23 - Service: Google Software Updater (gusvc) - Google - C:\Program Files\Google\Common\Google Updater\GoogleUpdaterService.exe
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Common Files\InstallShield\Driver\1050\Intel 32\IDriverT.exe
O23 - Service: iPod Service - Apple Inc. - C:\Program Files\iPod\bin\iPodService.exe
O23 - Service: Java Quick Starter (JavaQuickStarterService) - Sun Microsystems, Inc. - C:\Program Files\Java\jre6\bin\jqs.exe
O23 - Service: Pml Driver - HP - C:\WINDOWS\system32\HPHipm09.exe

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