You can change the Start Menu bitmap and word label.
This option was never designed to be a user option. To change Start Menu's Start label, you have to use a hex editor and edit EXPLORER.EXE . Search for
53 00 74 00 61 00 72 00 74 00
which is hex for the word Start. You can use any word you wish as long as it
is 5 characters or less. Leave the null characters alone (00). You are editing a
program. If you do not want to leave explorer unusable, you best try this with a
copy. Replace all copies of 53 00 74 00 61 00 72 00 74 00
with the word of your choice.
The flag bitmap can be replaced by a bitmap of your choice if its the same
size. The bitmap is embedded in USER.EXE which is found
in %systemroot%\system32. Using a copy of user.exe and an icon editor, change
the flag icons with your bitmap. There are at least two flag icons, sized 16x16
and 22x22 which need to be replaced. The different icons are there to support
different screen resolutions.
If you are careful and use copies of the executables, you can make these
changes. I have actually made these kinds of changes as an experiment. These
kinds of bit twiddling were common in the days of DOS and Win3.x. But I
personally wouldn't recommend it.