If you understand how it works, it's fairly easy to sort out.
HnS UI.exe is just a gui which creates a custom grub menu.lst for you.
It places a null file on each of your partitions (e.g. Vista.C.HnS) just as a label which the menu.lst can use to locate everything for the purpose of hiding/unhiding as necessary. The .xpm.gz file is just the background image for the grub boot menu.
All of that is uncontroversial and does nothing but occupy a tiny amount of HDD space.
The "active" part of the process, is the final step, where it renames the "real" MS bootmgr (375kb) to bootmgr.hns and renames the Grub4Dos module (grldr, 185kb) to bootmgr, so that the MBR finds the "fake" bootmgr at IPL instead of the real one.
The fake bootmgr (grub) can do what no MS bootloader can, it issues the hide/unhide commands in the custom-built menu.lst, and then chains control to the "real" bootmgr(.hns), or to XP's NTLDR depending on your choice.
You can see which version of bootmgr is in control by looking at the size, and revert to standard MS boot by simply renaming the two. All of the other files are completely inactive when the MS boot is "native", and can be deleted at your will. (you need to clean them up before you try a reinstall, to avoid causing the Beta install process problems).
Incidentally, you don't
need to use HnS at all, unless the
MS hack doesn't work for you. (It didn't for me, but does for most)