Dollar+sign+hf+mig+Dollar+sign


 * Dollar sign hf_mig Dollar sign **

One folder you should not delete is: $hf_mig$

(and any folders that a part of/contained in $hf_mig$)

It is a necessary folder for future updates

See the "Notes" section near the bottom of the following KB article:

@http://support.microsoft.com/default.aspx?scid=kb;en-us;824994

Basically what the note in Knowledge Base article implies is that when Windows is installing an update and that update contains an older version of a .dll file than what you currently are using (the newer version having been installed by an earlier update), Windows update will use the version of the.dll file which is located in one of the %windir%\$hf_mig$ sub-folders instead of the older version of the .dll that is part of the update your are currently in the process of installing.