Notpad as of v2.4 now includes its own spell checking facilities. If you want to install this additional feature then see Installing the Spell Checker.
The Spell checker in Notpad comes installed with two dictionaries. They are:
SSCEAM.TLX American English main lexicon.
SSCEBR.TLX British English main lexicon.
To change between the two use the Dictionaries Dialog dialog
See Also