missing dll files

I am having a problem with my Word spell check. Each time I do a spellcheck
in my document, first it does not pick upp all of the simple misspellings
because I misspell on purpose at times to check, and second I always get the
message I am missing MSSPELL3.DLL, MSSPELL32.DLL AND MSGR32.DLL, the last one
I cannot find anywhere. I check my folder and sure enough they are there so I
reinsert them, override, but when I start Word again and do a spell check I
go through it all over again. Any idea why it keeps doing this or how to make
it stay put once I reinsert it in the office folder and any idea how to get
the spellchecker to work correctly or why is isn't working right??? It is
set for English language and I am running XP.

Thanks for the help.>>