I always compose my messages in Word, then copy and paste them into the Forum. Word is set up to automatically alert me to a possible spelling error, and I can easily fix it before I post the message.
If you have any program that allows the spell check in outlook express to work you can just open a send to e-mail and leave it on the desk top and cut and paste to it. That is the way I use to do it but I have been using a little program that Attw turned us on to a while back. But it has one little side effect. when you use it to check your spelling and if you go to add more to your post it will set the ALT key so that when you hit F,A,E,V,T,H, It will cause the corresponding drop down menu to open. I'm use to it now since the forum one wouldn't recognize most of the common electrical terms and many other word's It's not a bad program and does a good job for spelling.
dont worry about the spelling, just send the messages/replies etc....not many on this site can get past the first round of a 2 person spelling bee including ME