Disaster. Please help. XP showing weird characters

From: Bob Cunningham (exw6sxq_at_earthlink.net)
Date: 02/16/04 

Date: Mon, 16 Feb 2004 10:28:14 GMT

I'm suddenly getting weird characters in all messages and
labels displayed by the OS. Somehow the OS seems to be
working from a crazy code page.

Characters are okay in newsreader message lists and in the
newsreader editor.

Weird charcters start with the "Welcome" message XP starts
with when I boot. When I select "Start", all of the options
are in the weird characters. The "Start" button itself is
labeled with the weird characters.

The problem is systematic in that I can see the same weird
character appearing every place a given letter should be,
except that the first character in a string is a little
square.

"a" is a check mark. "r" is a big "X". "s" is a question
mark. "n" is a large filled circle. "i" is a small filled
circle. "h" is a medium-sized filled circle. "g" is a
large filled square.

A lot of the other characters have signs that I now
recognize, but they're hard to describe.

I can bring up the DOS emulator, and I've been able to write
the Help for "Format" into a file that I can read in "Edit".
I'm about ready to reformat my C: drive and re-install XP.
Is there something I can do that's not so drastic? Can I
even format the hard disk from the DOS emulator? If not, is
there any way I can re-format without being able to read any
of the options in the Start menu?

The only unusual thing I did that I can think of is that I
inadvertently booted with an Encyclopedia Britannica
installation disk in the CD drive.

Any help anyone cares to give me will be greatly
appreciated.