strange delay

[CSULB71]

For the past couple of weeks, usually the first time that I hover the cursor over "all programs" (start menu) in Win XP, it takes a few seconds for the list of programs/icons to display, and hovering over one of those that has a sub-menu of several items, it takes another few seconds for the sub-items to display. Even worse, the 12 items I have "hidden" on the quick-launch toolbar take about 10 seconds to display. After a list has been displayed, the next time the cursor is hovered over an item, the list pops up quickly. Before this started happening, the lists would always appear almost instantly. SMART data says the hard drive is "healthy", and checking the RAM with MemTest-86 showed no errors. What might these delays be a symptom of?
Thanks.

[Soopafresh]

Could be several reasons.

There might be another process running (virus check?) which would slow down your system

Your drive needs defragging

Your Windows is suffering from "Bit Rot". Time to reinstall for that new computer smell.

[CSULB71]

No other app's running -- Task Mgr/"System Idle Process SYSTEM" = 98-99%.
Drive was de-fragged a few days ago (even tho XP said it wasn't needed).
"Bit Rot"? Maybe, but XP is supposed to be stable, right? Just in case, is there a way to re-install the OS without touching my program app's and data?

[MOVIEGEEK]

Just in case, is there a way to re-install the OS without touching my program app's and data?

When you do a clean install it erases all programs and data.
Hit Ctrl-Alt-Delete and go to Performance, make sure the CPU and Page File usage is low. If usage is high then you probably have programs running in the background, turn off the programs or buy more RAM. You also might have acquired some malware so run a system scan with your AV programs(Norton,MalwareBytes,etc).

[JohnnyMalaria]

Check you don't have any network shares that aren't connected. i.e., if you have a z: drive mapped to another computer and it isn't connected, you can experience significant delays due to network timeouts.

[CSULB71]

I was thinking about some sort of a "repair" install of the OS, not a complete (clean) install. I think they used to call that an "over-lay" in Win 98SE days?

I did a MalwareBytes scan, nothing found.

No other computers involved, so no network shares issue.

I have 1 GB of RAM, and there are no more programs/apps running in the background than there were before this all started. CPU usage is usually 2%-4% at "idle", and page file usage is shown at ~350MB (out of 768MB specified).

I believe this problem has something to do with displaying icons, because I also noticed when I right click Start/explore, the files listing (folder options = show as "details") under any particular folder pop up almost immediately, but the associated icons are slower to display -- only 2 or 3 icons per second appear. Where do the icons reside, and can a virus affect just one thing like that?