Leftover folders from downloaded updates?

Recently installed Windows XP Pro over Win98. Being a
good little computer owner, one of the first things I did
after the installation was to check for and install any
existing patches, updates, and hot-fixes.

What I have now are three folders on my hard drive with
ridicuosly long alpha-numeric names. For example:
bf1f335977981eed88754adf9afbf is the name of one folder.

Each folder has subfolder named sp2. Sp2 has a subfolder
named update.

Is this leftover from an installation that didn't clean
up its mess before ending? Can I delete these folders?

Thanks,

Jeff