Have you run this program if not do so,

Please download Malwarebytes' Anti-Malware to your desktop. Click here
Double Click mbam-setup.exe to install the application.
 Make sure a checkmark is placed next to Update Malwarebytes' Anti-Malware and Launch Malwarebytes' Anti-Malware, then click Finish.
 If an update is found, it will download and install the latest version.
 Once the program has loaded, select "Perform Full Scan", then click Scan.
 The scan may take some time to finish,so please be patient.
 When the scan is complete, click OK, then Show Results to view the results.
 Make sure that everything is checked, and click Remove Selected.
 When disinfection is completed, a log will open in Notepad and you may be prompted to Restart.(See Extra Note)
 The log is automatically saved by MBAM and can be viewed by clicking the Logs tab in MBAM.
 Copy&Paste the entire report in your next reply.
Extra Note:
If MBAM encounters a file that is difficult to remove,you will be presented with 1 of 2 prompts,click OK to either and let MBAM proceed with the disinfection process,if asked to restart the computer,please do so immediately

Then run this program,

Download ATF Cleaner by Atribune to your Desktop.

Note: Vista users must use Run As Administrator
 Under Main: Select Files to Delete choose: Select All.
 Click the Empty Selected button.
 If you use Firefox browser click Firefox at the top and choose: Select All
 Click the Empty Selected button.
If you would like to keep your saved passwords click No at the prompt.
 If you use Opera browser click Opera at the top and choose: Select All
 Click the Empty Selected button.
If you would like to keep your saved passwords click No at the prompt.
 Click Exit on the Main menu to close the program.

in answer yes sp3 can be uninstalled through add remove programs.

512Ram, 6 yrs old. old computer which suddenly became so slow.

I think we want to look at the computer closer before we uninstall Service packs,

We have no idea what anti virus is running, and what cleaning tools were used,

512Ram, 6 yrs old. old computer which suddenly became so slow.

I think we want to look at the computer closer before we uninstall Service packs,

We have no idea what anti virus is running, and what cleaning tools were used,

Sorry double post

Thanks all, the problem was solved by uninstalling ITunes. Zep, I'm an old member of this forum and have everything recommended running on all my machines. I knew it wasn't malware as I had just run all the scans.

Before taking out SP3, I uninstalled ITunes, ran a clean-up and it was back to normal. The machine is running low on memory and I think ITunes but it over the edge.

Thanks for all the great advice,

Jane

PS: I left SP3 on the computer.

OK,
jane glad it's sorted out.

You need to add some more Ram if the computer can handle it, XP needs at least 1 GB of operate efficiently.