Hi there, I hope you can help me...

Over the past few months my pc has slowed considerably. I have noticed the pc is affected both while running programs and the speed at which my pc connects to the internet. Heres a list of the things I have done to combat this problem (to no avail).

• Firstly I downloaded 'Malwarebytes' and performed a scan. I found a few malware viruses, which I deleted, rebooted and again run a scan.
• Secondly I downloaded 'Kaspersky Rescue Disk' which found a number of trojans and malware viruses. Again I ran the scan and it found no further problems. 
• After doing this I contacted Virgin as I was recieving a extremely slow connection speed to the internet (around 0.5mbs). I wasn't sure if these two problems were seperate. He installed a new modem and other computers around the house are running at 20mbs. My computer when using www.speedtest.net peeks at 20mbs but instantly goes down again. The virgin tech guy showed me on other pc's that the internet connection remains at 20mbs throughout the test (not peeking momentarily).

At this stage had it not been my work pc i would have just reinstalled windows but i can not afford to loose data or programs.

• I then downloaded sysinternals processes explorer and found my 'hardware and interrupts' running on average at 50%. This is the case even while no programs are running and when they are this shoots up to 100%. 
• I checked both my primary and secondary drivers are both running on DMA (not POI).
• I downloaded Hijack this. Here is a copy of my scan:

Logfile of Trend Micro HijackThis v2.0.4
Scan saved at 02:30:25, on 08/02/2012
Platform: Windows XP SP3 (WinNT 5.01.2600)
MSIE: Internet Explorer v8.00 (8.00.6001.18702)
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:\WINDOWS\system32\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\Java\jre6\bin\jqs.exe
C:\Program Files\Common Files\LightScribe\LSSrvc.exe
C:\WINDOWS\system32\HPZipm12.exe
C:\Program Files\Ralink\Common\RalinkRegistryWriter.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\system32\SearchIndexer.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\system32\wscntfy.exe
C:\Program Files\Malwarebytes' Anti-Malware\mbamservice.exe
C:\WINDOWS\system32\igfxpers.exe
C:\WINDOWS\system32\hkcmd.exe
C:\PROGRA~1\Eraser\Eraser.exe
C:\Program Files\Malwarebytes' Anti-Malware\mbamgui.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Ralink\Common\RaUI.exe
C:\WINDOWS\usb-audio.deAAVersaPort\CONTROLVERSAPORT.EXE
C:\WINDOWS\system32\wuauclt.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\Program Files\Mozilla Firefox\plugin-container.exe
C:\Program Files\Trend Micro\HiJackThis\HiJackThis.exe
C:\WINDOWS\system32\SearchProtocolHost.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://www.dell.co.uk/myway
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://bfc.myway.com/search/de_srchlft.html?p=DK
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = www.facebook.com
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
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = http://go.microsoft.com/fwlink/?LinkId=69157
R1 - HKCU\Software\Microsoft\Internet Connection Wizard,ShellNext = http://www.dell.co.uk/myway
R3 - URLSearchHook: (no name) - {A3BC75A2-1F87-4686-AA43-5347D756017C} - (no file)
O2 - BHO: AcroIEHelperStub - {18DF081C-E8AD-4283-A596-FA578C2EBDC3} - C:\Program Files\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll
O2 - BHO: (no name) - {5C255C8A-E604-49b4-9D64-90988571CECB} - (no file)
O2 - BHO: DriveLetterAccess - {5CA3D70E-1895-11CF-8E15-001234567890} - C:\WINDOWS\system32\dla\tfswshx.dll
O2 - BHO: Java(tm) Plug-In SSV Helper - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre6\bin\ssv.dll
O2 - BHO: Windows Live Sign-in Helper - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files\Common Files\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O2 - BHO: Java(tm) Plug-In 2 SSV Helper - {DBC80044-A445-435b-BC74-9C25C1C588A9} - C:\Program Files\Java\jre6\bin\jp2ssv.dll
O2 - BHO: JQSIEStartDetectorImpl - {E7E6F031-17CE-4C07-BC86-EABFE594F69C} - C:\Program Files\Java\jre6\lib\deploy\jqs\ie\jqs_plugin.dll
O3 - Toolbar: (no name) - {CCC7A320-B3CA-4199-B1A6-9F516DD69829} - (no file)
O4 - HKLM\..\Run: [SoundMAXPnP] C:\Program Files\Analog Devices\Core\smax4pnp.exe
O4 - HKLM\..\Run: [ISUSPM Startup] C:\PROGRA~1\COMMON~1\INSTAL~1\UPDATE~1\ISUSPM.exe -startup
O4 - HKLM\..\Run: [igfxtray] C:\WINDOWS\system32\igfxtray.exe
O4 - HKLM\..\Run: [igfxpers] C:\WINDOWS\system32\igfxpers.exe
O4 - HKLM\..\Run: [igfxhkcmd] C:\WINDOWS\system32\hkcmd.exe
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\QTTask.exe" -atboottime
O4 - HKLM\..\Run: [MSConfig] C:\WINDOWS\PCHealth\HelpCtr\Binaries\MSConfig.exe /auto
O4 - HKLM\..\Run: [Adobe ARM] "C:\Program Files\Common Files\Adobe\ARM\1.0\AdobeARM.exe"
O4 - HKLM\..\Run: [Malwarebytes' Anti-Malware] "C:\Program Files\Malwarebytes' Anti-Malware\mbamgui.exe" /starttray
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - HKUS\S-1-5-18\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'SYSTEM')
O4 - HKUS\.DEFAULT\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'Default user')
O4 - Startup: VersaPort Control Panel.lnk = ?
O4 - Global Startup: Ralink Wireless Utility.lnk = C:\Program Files\Ralink\Common\RaUI.exe
O9 - Extra button: (no name) - {3B8FB116-D358-48A3-A5C7-DB84F15CBB04} - http://www.expresstoolie.com/redirect.php (file missing)
O9 - Extra 'Tools' menuitem: IExplorer Security - {3B8FB116-D358-48A3-A5C7-DB84F15CBB04} - http://www.expresstoolie.com/redirect.php (file missing)
O9 - Extra button: (no name) - {CD67F990-D8E9-11d2-98FE-00C0F0318AFE} - (no file)
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 (file missing)
O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe (file missing)
O15 - Trusted Zone: *.line6.net
O22 - SharedTaskScheduler: Browseui preloader - {438755C2-A8BA-11D1-B96B-00A0C90312E1} - C:\WINDOWS\system32\browseui.dll
O22 - SharedTaskScheduler: Component Categories cache daemon - {8C7461EF-2B13-11d2-BE35-3078302C2030} - C:\WINDOWS\system32\browseui.dll
O23 - Service: Adobe LM Service - Adobe Systems - C:\Program Files\Common Files\Adobe Systems Shared\Service\Adobelmsvc.exe
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Common Files\InstallShield\Driver\1150\Intel 32\IDriverT.exe
O23 - Service: Java Quick Starter (JavaQuickStarterService) - Sun Microsystems, Inc. - C:\Program Files\Java\jre6\bin\jqs.exe
O23 - Service: Kodak AiO Network Discovery Service - Eastman Kodak Company - C:\Program Files\Kodak\AiO\Center\ekdiscovery.exe
O23 - Service: LightScribeService Direct Disc Labeling Service (LightScribeService) - Hewlett-Packard Company - C:\Program Files\Common Files\LightScribe\LSSrvc.exe
O23 - Service: MBAMService - Malwarebytes Corporation - C:\Program Files\Malwarebytes' Anti-Malware\mbamservice.exe
O23 - Service: NBService - Nero AG - C:\Program Files\Nero\Nero 7\Nero BackItUp\NBService.exe
O23 - Service: Intel NCS NetService (NetSvc) - Intel(R) Corporation - C:\Program Files\Intel\PROSetWired\NCS\Sync\NetSvc.exe
O23 - Service: NMIndexingService - Nero AG - C:\Program Files\Common Files\Ahead\Lib\NMIndexingService.exe
O23 - Service: Pml Driver HPZ12 - HP - C:\WINDOWS\system32\HPZipm12.exe
O23 - Service: Ralink Registry Writer (RalinkRegistryWriter) - Ralink Technology, Corp. - C:\Program Files\Ralink\Common\RalinkRegistryWriter.exe

--
End of file - 6975 bytes

**NOTE I WAS USING FIREFOX WHILST RUNNING THIS SCAN.

MY SYSTEM:

DELL MICROSOFT XP HOME EDITION 2002, SERVICE PACK 3, DELL DIMENSION DIM3000, INTEL (R) CELERON (R) CPU 3.06GHZ 512MB RAM

I hope someone can help me with this as I rely on my pc to make a living and its almost become unusable.

Thanks in advance.

Luke.