Files in Hotfixes in a UNIPROC folder?

[fdv]

Quick question, let's take (for example) Windows2000-KB908506-x86-ENU.EXE

If you expand it, it has a file in it, WINSRV.DLL, that appears twice -- once in the hotfix and again in a UNIPROC subfolder.

Now in this case, they happen to be identical, so who knows why Microsoft did this, but when HFSLIP runs, how does it determine which file to use?

[Tomcat76]

WINSRV.DLL -> SOURCESS\I386

UNIPROC\WINSRV.DLL -> SOURCESS\I386\UNIPROC

MS are usually kind enough to keep the directory structure of the installation CD.