Online videos play choppy. It's getting worse, and I don't know how to fix it.

It never did this before, but for a few weeks, all online videos play choppy, even when fully loaded.  They'll almost like sputter.
I don't have the nicest computer in the world, but it never did this before.  I use firefox.  I have the latest version of flash.  Have updated the drivers.  I really don't know what else to do, and I watch online videos all the time.  It's not just one site.  It's every video site that I've tried.  Any help would be appreciated as I am out of ideas.  Thanks.

Have you changed any hardware or software coincident to the change? Have you been getting any kind of error messages when doing tasks on the computer? What occurs re this phenomenon if you use another browser? How do non web videos perform such as dvd's or stored videos on your HDD? truenorth

No.  I haven't changed anything at all.  There have been do error messages.  I have tried 3 different web browsers.  DVDs and stored videos seem to play fine.

What type of ISP connection are you using? What kind of speeds are you getting on it? Have you installed all the updates for the XP  O/S particularly SP3? truenorth

Hard drive running out of space, causing caching to slow everything down?
Too many programs running in the background causing the CPU to be busy all the time?

I have DSL at the same speed it's always been.  I'm not running out of hard drive space.  It's basically acting as though there are a lot of other programs running at the same time that I'm trying to watch a video, like a scan or something.  The thing is,  there isn't anything running in the background to use up CPU.  I have been trying to figure this out for about three weeks now, and am completely stumped. 

You tried emptying the cache on all your browsers?
Reinstalling and/or updating Flash?

Yup, all cache's been emptied.  I've uninstalled, reinstalled flash.  Even installed earlier versions, but nothing.  It's actually been worse today than it has been.

[Moderator]

Sounding more and more like a connection issue to me...
Travel to SpeedTest.net and see what your results are...compare them to what your ISP says they should be...

PS if you have wireless setup in your home your neighbors may be stealing signal...which will result in slower speeds...
Review your security settings if the above is the case.

Download Minitool box from this link http://www.bleepingcomputer.com/forums/topic398507.html
Checkmark only List Installed Programs and List Users, Partitions and Memory size and click Go. Follow the instruction to copy/paste the result here.

The speed test is the same that it's always been, and I have a wired connection. 

MiniToolBox by Farbar
Ran by Compaq_Owner (administrator) on 10-01-2012 at 04:22:00
Microsoft Windows XP Home Edition Service Pack 3 (X86)
Boot Mode: Normal
***************************************************************************

=========================== Installed Programs ============================

 Sansa Media Converter (Version: 1.0-B4.256)
32 Bit HP CIO Components Installer (Version: 6.1.1)
Actiontec Gateway
Adobe AIR (Version: 2.0.2.12610)
Adobe Flash Player 11 ActiveX (Version: 11.1.102.55)
Adobe Flash Player 11 Plugin (Version: 11.1.102.55)
Adobe Reader 9.4.6 (Version: 9.4.6)
Adobe Shockwave Player 11.5 (Version: 11.5.9.620)
Agere Systems PCI Soft Modem
alightedcmasth.zip
Any DVD Converter Professional 4.2.7
Avira AntiVir Personal - Free Antivirus (Version: 10.2.0.704)
Big Fish Games: Game Manager (Version: 3.0.1.60)
BufferChm (Version: 130.0.331.000)
Burger Shop 2
CCleaner (Version: 3.13)
Copy (Version: 130.0.366.000)
Destinations (Version: 130.0.0.0)
DeviceDiscovery (Version: 130.0.372.000)
DJ_AIO_05_F4400_Software_Min (Version: 130.0.448.000)
Eusing Free Registry Cleaner
F4400 (Version: 130.0.448.000)
FastStone Photo Resizer 3.1 (Version: 3.1)
Free RAR Extract Frog (Version: 3.23)
GIMP 2.6.11 (Version: 2.6.11)
GoBit Games Plugin v1.5
GPBaseService2 (Version: 130.0.371.000)
GSplit 3 (Version: 3.0.1.0)
Help and Support Additions
HP Customer Participation Program 13.0 (Version: 13.0)
HP Deskjet F4400 Printer Driver Software 13.0 Rel .5 (Version: 13.0)
HP Imaging Device Functions 13.0 (Version: 13.0)
HP Print Projects 1.0 (Version: 1.0)
HP Smart Web Printing 4.5 (Version: 4.5)
HP Solution Center 13.0 (Version: 13.0)
HP Update (Version: 5.002.005.003)
hpPrintProjects (Version: 130.0.303.000)
HPProductAssistant (Version: 130.0.371.000)
HpSdpAppCoreApp (Version: 3.00.0000)
hpWLPGInstaller (Version: 130.0.303.000)
ieSpell (Version: 2.5.1 (build 106))
InterVideo WinDVD Player (Version: 5.0-B11.533)
Java Auto Updater (Version: 2.0.6.1)
Java(TM) 6 Update 30 (Version: 6.0.300)
KBD
Malwarebytes Anti-Malware version 1.60.0.1800 (Version: 1.60.0.1800)
MarketResearch (Version: 130.0.374.000)
Media Player Utilities 5.22 (Version: 5.22)
Microsoft .NET Framework 1.1 (Version: 1.1.4322)
Microsoft .NET Framework 1.1 Security Update (KB2572067)
Microsoft .NET Framework 1.1 Security Update (KB979906)
Microsoft .NET Framework 2.0 Service Pack 2 (Version: 2.2.30729)
Microsoft .NET Framework 3.0 Service Pack 2 (Version: 3.2.30729)
Microsoft .NET Framework 3.5 SP1
Microsoft .NET Framework 3.5 SP1 (Version: 3.5.30729)
Microsoft Application Error Reporting (Version: 12.0.6012.5000)
Microsoft Kernel-Mode Driver Framework Feature Pack 1.7
Microsoft Visual C++ 2005 ATL Update kb973923 - x86 8.0.50727.4053 (Version: 8.0.50727.4053)
Microsoft Visual C++ 2005 Redistributable (Version: 8.0.61001)
Microsoft Visual C++ 2008 Redistributable - x86 9.0.21022 (Version: 9.0.21022)
Microsoft Visual C++ 2008 Redistributable - x86 9.0.30729.17 (Version: 9.0.30729)
Microsoft Visual C++ 2008 Redistributable - x86 9.0.30729.4148 (Version: 9.0.30729.4148)
Microsoft Visual C++ 2008 Redistributable - x86 9.0.30729.6161 (Version: 9.0.30729.6161)
Microsoft WinUsb 1.0
Mozilla Firefox 9.0.1 (x86 en-US) (Version: 9.0.1)
MSXML 4.0 SP2 (KB954430) (Version: 4.20.9870.0)
MSXML 4.0 SP2 (KB973688) (Version: 4.20.9876.0)
PC-Doctor for Windows (Version: 1.06.002)
PS2
Python 2.2 combined Win32 extensions
Python 2.2.1 (Version: 2.2.1)
QuickConnect (Version: 3.5)
S3 S3Display
S3 S3Gamma2
S3 S3Info2
S3 S3Overlay
S3GSetup (Version: 2.00.07.0709)
Scan (Version: 13.0.0.0)
Security Task Manager 1.7h (Version: 1.7h)
Simple Adblock (Version: 1.1.0)
SmartWebPrinting (Version: 130.0.373.000)
SolutionCenter (Version: 130.0.373.000)
Status (Version: 130.0.373.000)
SUPERAntiSpyware (Version: 5.0.1118)
Toolbox (Version: 130.0.648.000)
TrayApp (Version: 130.0.376.000)
TuxGuitar (Version: 1.2)
VC 9.0 Runtime (Version: 1.0.0)
Veoh Web Player (Version: 1.1.2.0000)
VIA Rhine-Family Fast-Ethernet Adapter
VIA/S3G Display Driver
VistaMizer 3.3.0.0 (Version: 3.3.0.0)
Visual C++ 2008 x86 Runtime - (v9.0.30729) (Version: 9.0.30729)
Visual C++ 2008 x86 Runtime - v9.0.30729.01 (Version: 9.0.30729.01)
VLC media player 1.1.11 (Version: 1.1.11)
WebFldrs XP (Version: 9.50.7523)
WebReg (Version: 130.0.132.017)
Windows Media Format 11 runtime
Windows Media Player 11
WinRAR 4.01 (32-bit) (Version: 4.01.0)
WinX Free DVD Ripper 4.5.14
WinX Free PSP Video Converter 3.2.21

========================= Memory info: ===================================

Percentage of memory in use: 55%
Total physical RAM: 959.48 MB
Available physical RAM: 423.63 MB
Total Pagefile: 1549.91 MB
Available Pagefile: 937.24 MB
Total Virtual: 2047.88 MB
Available Virtual: 1965.93 MB

========================= Partitions: =====================================

1 Drive c: (PRESARIO) (Fixed) (Total:31.93 GB) (Free:16.96 GB) NTFS
2 Drive d: (PRESARIO_RP) (Fixed) (Total:5.32 GB) (Free:0.89 GB) FAT32

========================= Users: ========================================

User accounts for \\TOKYO

Administrator            ASPNET                   Compaq_Owner             
Guest                    HelpAssistant            SUPPORT_388945a0         
SUPPORT_fddfa904         


**** End of log ****

You need to run a spyware scan and get rid of some of those entries. Use Microsoft Security Essentials.

Also if i might suggest you need to free up some space on your Fat 32 drive "D" as it is very low on available space. truenorth

[Moderator]

Also if i might suggest you need to free up some space on your Fat 32 drive "D" as it is very low on available space. truenorth

D: is most likely the Recovery partition and shouldn't be modified...