Hello there, sorry for the delay.
I see nothing particularly wrong in your logs, and with your pretty decent specifics, I'm not sure off-hand now as to what may cause this problem.
Download:
CCleaner (freeware)
|MG| Free Download - CCleaner Slim (No Yahoo Toolbar, English) 1.37.456
Run the installer, and uncheck the option to install Yahoo toolbar
(unless you want Yahoo toolbar).
Once installed, run
CCleaner click the Windows [tab]
Select the following:

Next: click
Options click the
Settings tab
Uncheck: "Only delete files older than 48 hrs.", click Ok
Then click
Run Cleaner (bottom right) then
Exit
Note: Please do
NOT use the
Applications tab or the
Issues icon. Keep to the
Cleaner icon and the
Windows tab.
Manual steps to run Chkdsk from My Computer or Windows Explorer
Double-click My Computer, and then right-click the hard disk that you want to check
Click Properties, and then click Tools.
Under Error-checking, click Check Now. A dialog box that shows the Check disk options is displayed
To repair errors without scanning the volume for bad sectors, select the Automatically fix file system errors check box, and then click Start
To repair errors, locate bad sectors, and recover readable information, select the Scan for and attempt recovery of bad sectors check box, and then click Start.
I suggest clicking both boxes.
It will ask "Do you want to schedule the disk check to occur the next time you restart the computer?"
Click Yes to schedule the disk check, and then restart your computer to start the disk check.
Next go to Start > Run.
Type in
sfc /scannow
Note you may be asked for your Windows XP CD if errors are found.
How to reinstall or repair Internet Explorer and Outlook Express in Windows XP for the sfc /scannow instructions
You can run a test at PCPitStop. Please register (it's free) with PCPitStop and run the full tests
Welcome to PC PitStop!
This is an excellent diagnostics scan that may help in determining problems not related to malware. When the tests are complete, a results page will pop up. Click "Share these results with TechExpress" on the left-hand side. Then copy the URL provided and post it here for review.
You might want to take a look at this page created by miekiemoes, one of the Global Moderators here, on slow systems, and some things you can try to do to try to improve it:
http://users.telenet.be/bluepatchy/miekiem...owcomputer.html
In your next post please post
Tech link results from PCPitStop and a
new HJT log.