I have problem i cant type farsi in my web builder,i used to be able to type farsi then i started to install c?

i have problem i cant type farsi in my web builder,i used to be able to type farsi then i started to install cople of extentions..now im not able...i uninstall and re installed web builder many times...but i still have a problem...i tried to install web builder in another computer and it wored fine do you know how can i remove all of the items related my web builder..cause i dont want to re install windows ....but seems like i have to remove all of the infos related to my web builder...may be in registry files .but i dont know which file should i remove exactly in rgistry thanks for help