Folders open very slow after updates

I have a fresh re-load of windows xp pro on a new hard drive.
After the re-load all was running well and very fast.
When I would click on a folder with a large number of photos it would only
take a few seconds before all the thumbnails were displayed.
I did all the windows updates to bring the install up to date and now the
same folder takes as much as 30 seconds to load the very same folder's
thumbnails.
What element of the update did this?
Please help.
I assumed it was a hardware issue so I purchased new ram and another
harddrive and went through the tidious process of re-loading the OS again
just to have the problem resurface after the updates.