Why do some MS-updates leave GUID-folders behind?

[spinjector]

Why do some Microsoft Updates leave GUID-named folders behind on the C: drive? Is this a design. or a byproduct?

For example: C:\56ec6c94dc7adab4bbc4fb8313863f. This is for "Microsoft system driver files for XPSDrv print drivers", according to the INF file.

[cluberti]

Usually all that's left is a log - it's probably meant to be hidden and removed after install, but isn't (for whatever reason). These are safe to delete, fwiw, but as to why it's left behind it would probably be specific to the update (usually msxml updates are the worst offenders, for example).