Video stuttering on playback

Hello all, I've officially reached the end of my limited knowledge on how to fix problems of this nature.

Whenever I try to view a video file of any extension type in any player I might use (the exception being mpg files played in Firefox) the video will stutter and drastically fluctuate in speed while the audio will continue to play normally. Here's the kicker, this just started yesterday. Files that played perfectly as of Friday no longer play properly at all.

My comp: I'm running a laptop and, due to my schedule and job, use it as my primary computer. AMD athlon XP2400+ 1.79GHz, 448 MB RAM.

The troubleshooting I've done is as follows: I've run Disk Cleanup; I've defragged using both the Windows defrag. and Vopt; I've checked with Winpatrol and with the task manager for anything chewing up too much power; I've tried running every file type I have through Windows Media, WinDVD, afreeCodecVT, and Firefox. So, my C: drive is spotless and has zero fragmented files on it; I can try opening video while my CPU usage is in the single digits (2% avg.) from a fresh start-up with no programs running and the problem simply won't go away.

I'll post a hijackthis log so hopefully, if it's not something glaringly obvious like needing new codecs, someone can find the major memory drain that's making my comp. work this hard to run videos. A random thought I had, and I could be way off base with this, but I recently fired LimeWire back up after an extended hiatus. I don't know if it's related, but it's the only major change in my usage between Friday and now.

Thanks in advance.

Logfile of Trend Micro HijackThis v2.0.0 (BETA)
Scan saved at 7:43:05 PM, on 9/9/2007
Platform: Windows XP SP2 (WinNT 5.01.2600)
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\Ati2evxx.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\Ati2evxx.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\Symantec\LiveUpdate\ALUSchedulerSvc.exe
C:\Program Files\Common Files\Symantec Shared\ccSvcHst.exe
C:\WINDOWS\system32\HPConfig.exe
C:\Program Files\HPQ\Notebook Utilities\HPWirelessMgr.exe
C:\Program Files\Common Files\Symantec Shared\AppCore\AppSvc32.exe
C:\Program Files\Wireless-G Portable USB Adapter Wireless Network Monitor\WLService.exe
C:\Program Files\Wireless-G Portable USB Adapter Wireless Network Monitor\WUSB54GPv4.exe
C:\WINDOWS\system32\carpserv.exe
C:\Program Files\HPQ\One-Touch\OneTouch.EXE
C:\Program Files\Synaptics\SynTP\SynTPLpr.exe
C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
C:\Program Files\Wireless-G Portable USB Adapter Wireless Network Monitor\InfoMyCa.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Documents and Settings\John\My Documents\uptimer4\Uptimer4.exe
C:\PROGRAM FILES\COMMON FILES\SYMANTEC SHARED\CCAPP.EXE
C:\Program Files\Proxomitron Naoko-4\Proxomitron.exe
C:\Program Files\Zone Labs\ZoneAlarm\zlclient.exe
C:\WINDOWS\system32\ZoneLabs\vsmon.exe
C:\WINDOWS\system32\drwtsn32.exe
C:\WINDOWS\system32\drwtsn32.exe
C:\Program Files\Common Files\Symantec Shared\CCPD-LC\symlcsvc.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\Documents and Settings\John\My Documents\Hijackthis\HiJackThis_v2.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
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://qus8l.hpwis.com/
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyServer = http=localhost:8080;https=localhost:8080
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 5.0\Reader\ActiveX\AcroIEHelper.ocx
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre1.5.0_08\bin\ssv.dll
O2 - BHO: (no name) - {FDD3B846-8D59-4ffb-8758-209B6AD74ACC} - (no file)
O4 - HKLM\..\Run: [CARPService] carpserv.exe
O4 - HKLM\..\Run: [Cpqset] C:\Program Files\HPQ\Default Settings\cpqset.exe
O4 - HKLM\..\Run: [PreloadApp] c:\hp\drivers\printers\photosmart\hphprld.exe c:\hp\drivers\printers\photosmart\setup.exe -d
O4 - HKLM\..\Run: [srmclean] C:\Cpqs\Scom\srmclean.exe
O4 - HKLM\..\Run: [Display Settings] C:\Program Files\HPQ\Notebook Utilities\hptasks.exe /s
O4 - HKLM\..\Run: [QT4HPOT] C:\Program Files\HPQ\One-Touch\OneTouch.EXE
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: [WUSB54GPv4] C:\Program Files\Wireless-G Portable USB Adapter Wireless Network Monitor\InvokeSvc3.exe
O4 - HKLM\..\Run: [AtiPTA] atiptaxx.exe
O4 - HKLM\..\Run: [IMJPMIG8.1] "C:\WINDOWS\IME\imjp8_1\IMJPMIG.EXE" /Spoil /RemAdvDef /Migration32
O4 - HKLM\..\Run: [MSPY2002] C:\WINDOWS\system32\IME\PINTLGNT\ImScInst.exe /SYNC
O4 - HKLM\..\Run: [PHIME2002ASync] C:\WINDOWS\system32\IME\TINTLGNT\TINTSETP.EXE /SYNC
O4 - HKLM\..\Run: [PHIME2002A] C:\WINDOWS\system32\IME\TINTLGNT\TINTSETP.EXE /IMEName
O4 - HKLM\..\Run: [osCheck] C:\PROGRAM FILES\NORTON ANTIVIRUS\osCheck.exe
O4 - HKLM\..\Run: [Symantec PIF AlertEng] C:\PROGRAM FILES\COMMON FILES\SYMANTEC SHARED\PIF\{B8E1DD85-8582-4C61-B58F-2F227FCA9A08}\PIFSvc.exe /a /m C:\Program Files\Common Files\Symantec Shared\PIF\{B8E1DD85-8582-4c61-B58F-2F227FCA9A08}\AlertEng.dll
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O14 - IERESET.INF: START_PAGE_URL=http://qus8l.hpwis.com
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: Ati HotKey Poller - ATI Technologies Inc. - C:\WINDOWS\system32\Ati2evxx.exe
O23 - Service: ATI Smart - Unknown owner - C:\WINDOWS\system32\ati2sgag.exe
O23 - Service: Automatic LiveUpdate Scheduler - Symantec Corporation - C:\Program Files\Symantec\LiveUpdate\ALUSchedulerSvc.exe
O23 - Service: Symantec Event Manager (ccEvtMgr) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccSvcHst.exe
O23 - Service: Symantec Settings Manager (ccSetMgr) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccSvcHst.exe
O23 - Service: Symantec Lic NetConnect service (CLTNetCnService) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccSvcHst.exe
O23 - Service: HP Configuration Interface Service (HPConfig) - Hewlett-Packard - C:\WINDOWS\system32\HPConfig.exe
O23 - Service: HPWirelessMgr - Hewlett-Packard Co. - C:\Program Files\HPQ\Notebook Utilities\HPWirelessMgr.exe
O23 - Service: Symantec IS Password Validation (ISPwdSvc) - Symantec Corporation - C:\Program Files\Norton AntiVirus\isPwdSvc.exe
O23 - Service: LiveUpdate - Symantec Corporation - C:\PROGRA~1\Symantec\LIVEUP~1\LUCOMS~1.EXE
O23 - Service: LiveUpdate Notice Service Ex (LiveUpdate Notice Ex) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccSvcHst.exe
O23 - Service: LiveUpdate Notice Service - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\PIF\{B8E1DD85-8582-4c61-B58F-2F227FCA9A08}\PIFSvc.exe
O23 - Service: Symantec Core LC - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\CCPD-LC\symlcsvc.exe
O23 - Service: Symantec AppCore Service (SymAppCore) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\AppCore\AppSvc32.exe
O23 - Service: TrueVector Internet Monitor (vsmon) - Zone Labs, LLC - C:\WINDOWS\system32\ZoneLabs\vsmon.exe
O23 - Service: WUSB54GPv4SVC - GEMTEKS - C:\Program Files\Wireless-G Portable USB Adapter Wireless Network Monitor\WLService.exe

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