i know you people might have come across such folders hiding under your drives and you must have pondered why are they and what is their use, well every thing microsoft does has got a reason so here it is...

These $NTUninstall folders are created when you install a Microsoft Service Pack, a hotfix, or certain security updates. Each KBnnnnnn represents an update from Microsoft. To gather more information about an update, type the following URL in your browser, replacing the string nnnnnn with the actual numbers. Don't include the prefixes Q or KB

http://support.microsoft.com/?kbid=nnnnnn

These folders contain the uninstall information for the update you install. That means that you will be unable to uninstall the updates if you delete these folders. You may leave them there unless you need hard drive space. If your system is stable, and if you no longer plan to uninstall an update, then go ahead and remove the corresponding $NtUninstall..... folders. Or you may move those folders to a different hard drive, or burn them to CD before deleting them from the hard drive.

Do NOT delete the $hf_mig$ folder anyway!