1 hour "warm up" needed

My PC was working fine in the morning when a few emails were exchanged and PC was then shut down.

After booting up quickly in the afternoon in the normal time, the PC then needed an hour or so before it would run at normal speed. Before then it took AGES to open links or applications.

After the hour warm-up period all is normal. The same thing is happening again today. Can you help explain this, please?

HiJackThis log file follows (Note - Main HDD is labelled E rather than C on this PC):

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 11:06:53, on 12/05/2008
Platform: Windows 2000 SP4 (WinNT 5.00.2195)
MSIE: Internet Explorer v5.00 (5.00.2920.0000)
Boot mode: Normal

Running processes:
E:\WINNT\System32\smss.exe
E:\WINNT\system32\winlogon.exe
E:\WINNT\system32\services.exe
E:\WINNT\system32\lsass.exe
E:\WINNT\system32\svchost.exe
E:\WINNT\system32\spoolsv.exe
E:\program files\a-squared free\a2service.exe
E:\Program Files\Grisoft\AVG Anti-Spyware 7.5\guard.exe
E:\Program Files\Comodo\CBOClean\BOCORE.exe
E:\Program Files\CA\eTrust Internet Security Suite\eTrust EZ Antivirus\ISafe.exe
E:\Program Files\Comodo\Firewall\cmdagent.exe
E:\WINNT\System32\svchost.exe
E:\WINNT\system32\hidserv.exe
E:\Program Files\Ahead\InCD\InCDsrv.exe
E:\WINNT\system32\MSTask.exe
E:\WINNT\system32\stisvc.exe
E:\Program Files\CA\eTrust Internet Security Suite\eTrust EZ Antivirus\VetMsg.exe
E:\Program Files\Webroot\Spy Sweeper\SpySweeper.exe
E:\WINNT\Explorer.EXE
E:\WINNT\System32\WBEM\WinMgmt.exe
E:\WINNT\system32\svchost.exe
E:\Program Files\CA\eTrust Internet Security Suite\eTrust EZ Antivirus\CAVRID.exe
E:\Program Files\CA\eTrust Internet Security Suite\cctray\cctray.exe
E:\WINNT\system32\starter.exe
E:\Program Files\Comodo\Firewall\CPF.exe
E:\PROGRA~1\Comodo\CBOClean\BOC425.exe
E:\Program Files\Webroot\Spy Sweeper\SpySweeperUI.exe
E:\Program Files\SUPERAntiSpyware\SUPERAntiSpyware.exe
E:\Program Files\Belkin\Belkin 802.11g Wireless PCI Card Configuration Utility\utility.exe
E:\Program Files\Webroot\Spy Sweeper\SSU.EXE
E:\Program Files\Trend Micro\HijackThis\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.virginmedia.com/
F2 - REG:system.ini: UserInit=E:\WINNT\system32\Userinit.exe
O2 - BHO: Adobe PDF Reader Link Helper - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - E:\Program Files\Adobe\Acrobat 7.0\ActiveX\AcroIEHelper.dll
O2 - BHO: Spybot-S&D IE Protection - {53707962-6F74-2D53-2644-206D7942484F} - E:\PROGRA~1\SPYBOT~1\SDHelper.dll
O2 - BHO: (no name) - {5C8B2A36-3DB1-42A4-A3CB-D426709BBFEB} - (no file)
O2 - BHO: EpsonToolBandKicker Class - {E99421FB-68DD-40F0-B4AC-B7027CAE2F1A} - E:\Program Files\EPSON\EPSON Web-To-Page\EPSON Web-To-Page.dll
O3 - Toolbar: EPSON Web-To-Page - {EE5D279F-081B-4404-994D-C6B60AAEBA6D} - E:\Program Files\EPSON\EPSON Web-To-Page\EPSON Web-To-Page.dll
O3 - Toolbar: @msdxmLC.dll,-1@1033,&Radio - {8E718888-423F-11D2-876E-00A0C9082467} - E:\WINNT\system32\msdxm.ocx
O4 - HKLM\..\Run: [NvCplDaemon] "RUNDLL32.EXE" E:\WINNT\system32\NvCpl.dll,NvStartup
O4 - HKLM\..\Run: [CAVRID] "E:\Program Files\CA\eTrust Internet Security Suite\eTrust EZ Antivirus\CAVRID.exe"
O4 - HKLM\..\Run: [cctray] "E:\Program Files\CA\eTrust Internet Security Suite\cctray\cctray.exe"
O4 - HKLM\..\Run: [EnsoniqMixer] starter.exe
O4 - HKLM\..\Run: [COMODO Firewall Pro] "E:\Program Files\Comodo\Firewall\CPF.exe" /background
O4 - HKLM\..\Run: [BOC-425] E:\PROGRA~1\Comodo\CBOClean\BOC425.exe
O4 - HKLM\..\Run: [SpySweeper] "E:\Program Files\Webroot\Spy Sweeper\SpySweeperUI.exe" /startintray
O4 - HKCU\..\Run: [SUPERAntiSpyware] "E:\Program Files\SUPERAntiSpyware\SUPERAntiSpyware.exe"
O4 - HKUS\.DEFAULT\..\RunOnce: [^SetupICWDesktop] E:\Program Files\Internet Explorer\Connection Wizard\icwconn1.exe /desktop (User 'Default user')
O4 - Global Startup: Adobe Reader Speed Launch.lnk = E:\Program Files\Adobe\Acrobat 7.0\Reader\reader_sl.exe
O4 - Global Startup: Belkin 802.11g Wireless PCI Card Configuration Utility.lnk = E:\Program Files\Belkin\Belkin 802.11g Wireless PCI Card Configuration Utility\utility.exe
O8 - Extra context menu item: E&xport to Microsoft Excel - res://E:\PROGRA~1\MICROS~2\OFFICE11\EXCEL.EXE/3000
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - E:\Program Files\Java\jre1.5.0_02\bin\npjpi150_02.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - E:\Program Files\Java\jre1.5.0_02\bin\npjpi150_02.dll
O9 - Extra button: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - E:\PROGRA~1\MICROS~2\OFFICE11\REFIEBAR.DLL
O9 - Extra button: Related - {c95fe080-8f5d-11d2-a20b-00aa003c157a} - E:\WINNT\web\related.htm
O9 - Extra 'Tools' menuitem: Show &Related Links - {c95fe080-8f5d-11d2-a20b-00aa003c157a} - E:\WINNT\web\related.htm
O9 - Extra button: (no name) - {DFB852A3-47F8-48C4-A200-58CAB36FD2A2} - E:\PROGRA~1\SPYBOT~1\SDHelper.dll
O9 - Extra 'Tools' menuitem: Spybot - Search & Destroy Configuration - {DFB852A3-47F8-48C4-A200-58CAB36FD2A2} - E:\PROGRA~1\SPYBOT~1\SDHelper.dll
O12 - Plugin for .spop: E:\Program Files\Internet Explorer\Plugins\NPDocBox.dll
O16 - DPF: ppctlcab - http://ppupdates.ca.com/downloads/scanner/ppctlcab.cab
O16 - DPF: {0EB0E74A-2A76-4AB3-A7FB-9BD8C29F7F75} (CKAVWebScan Object) - http://www.kaspersky.com/downloads/k...an_unicode.cab
O16 - DPF: {17492023-C23A-453E-A040-C7C580BBF700} (Windows Genuine Advantage Validation Tool) - http://go.microsoft.com/fwlink/?linkid=39204
O16 - DPF: {193C772A-87BE-4B19-A7BB-445B226FE9A1} (ewidoOnlineScan Control) - http://download.ewido.net/ewidoOnlineScan.cab
O16 - DPF: {2ED9BC2B-4DF1-472E-9B5E-55477D2C97F5} (Microsoft Data Collection Control) - https://support.microsoft.com/OAS/ActiveX/odc.cab
O16 - DPF: {2FC9A21E-2069-4E47-8235-36318989DB13} (PPSDKActiveXScanner.MainScreen) - http://ppupdates.ca.com/downloads/scanner/axscanner.cab
O16 - DPF: {56393399-041A-4650-94C7-13DFCB1F4665} (PSFormX Control) - http://www.pestpatrol.com/pestscan/pestscan.cab
O16 - DPF: {6414512B-B978-451D-A0D8-FCFDF33E833C} (WUWebControl Class) - http://update.microsoft.com/microsof...?1121688809000
O16 - DPF: {6E32070A-766D-4EE6-879C-DC1FA91D2FC3} (MUWebControl Class) - http://www.update.microsoft.com/micr...?1182504983078
O16 - DPF: {7B297BFD-85E4-4092-B2AF-16A91B2EA103} (WScanCtl Class) - http://www3.ca.com/securityadvisor/v...fo/webscan.cab
O16 - DPF: {84818113-96C5-11D2-BE39-006008BF4DD5} (ViewDirector Object) - http://subscribers.scotlandspeople.g...x/viewdw32.ocx
O16 - DPF: {9A9307A0-7DA4-4DAF-B042-5009F29E09E1} (ActiveScan Installer Class) - http://www.pandasoftware.com/activescan/as5/asinst.cab
O20 - Winlogon Notify: !SASWinLogon - E:\Program Files\SUPERAntiSpyware\SASWINLO.dll
O23 - Service: a-squared Free Service (a2free) - Emsi Software GmbH - E:\program files\a-squared free\a2service.exe
O23 - Service: AVG Anti-Spyware Guard - Anti-Malware Development a.s. - E:\Program Files\Grisoft\AVG Anti-Spyware 7.5\guard.exe
O23 - Service: BOCore - COMODO - E:\Program Files\Comodo\CBOClean\BOCORE.exe
O23 - Service: CaCCProvSP - CA, Inc. - E:\Program Files\CA\eTrust Internet Security Suite\ccprovsp.exe
O23 - Service: CAISafe - Computer Associates International, Inc. - E:\Program Files\CA\eTrust Internet Security Suite\eTrust EZ Antivirus\ISafe.exe
O23 - Service: Comodo Application Agent (CmdAgent) - COMODO - E:\Program Files\Comodo\Firewall\cmdagent.exe
O23 - Service: Logical Disk Manager Administrative Service (dmadmin) - VERITAS Software Corp. - E:\WINNT\System32\dmadmin.exe
O23 - Service: InCD Helper (InCDsrv) - Nero AG - E:\Program Files\Ahead\InCD\InCDsrv.exe
O23 - Service: InCD Helper (read only) (InCDsrvR) - Nero AG - E:\Program Files\Ahead\InCD\InCDsrv.exe
O23 - Service: NVIDIA Display Driver Service (NVSvc) - NVIDIA Corporation - E:\WINNT\System32\nvsvc32.exe
O23 - Service: VET Message Service (VETMSGNT) - CA, Inc. - E:\Program Files\CA\eTrust Internet Security Suite\eTrust EZ Antivirus\VetMsg.exe
O23 - Service: Webroot Spy Sweeper Engine (WebrootSpySweeperService) - Webroot Software, Inc. - E:\Program Files\Webroot\Spy Sweeper\SpySweeper.exe

--
End of file - 7883 bytes

I see no infection.