which hosting are you using, windows or linux. If you are using windows, then you no need to worry and if you are using simply go to the root by using FTP. deleted existing .htaccess by simple delete command.
In the permalink structure, choose another type of structure and apply and again choose your existing structure. This step is very important, it will create .htaccess.
You can read more at http://is.gd/LYLCxc
After you did it, just install wp-redirection plugin. You will never get a 404 error
I know this method, now I am following it, but what about previous post where I inserted image with link in it. How to disabled that.
