This policy turns off the autocorrect misspelled words option. This does not however prevent the user or an application from changing the setting programmatically. The autocorrect misspelled words option controls whether or not errors in typed text will be automatically corrected. If the policy is Enabled then the option will be locked to not autocorrect misspelled words. If the policy is Disabled or Not Configured then the user will be free to change the setting according to their preference. Note that the availability and function of this setting is dependent on supported languages being enabled.
Control Panel\Regional and Language Options
At least Windows Vista