My pc isn't checking spelling.Even during chat it doesn't underline the wrong spelling.
OS: windows 7 ultimate 64bit.
Enable it on browser. Or whichever program you are using.
You may want to double check if you have unchecked the option "Use a web service to help resolve spelling errors". If you have unchecked it, make sure that you have checked the option "Enable Spell Checking" and choose English or whatever language you prefer.