Similar to enabling the GD Library in the php.ini file, one can also enable the mbstring library in the php.ini file on their server.
By default, php comes with the mbstring library, however, it is disabled by a ‘comment out’ in the php.ini file within your server’s php directory.
This shouldn’t be a problem unless it is required, in which case there will be an error message telling you so.
I have personally run my server [ PHP/Apache/Windows/MySql ] without it enabled for a while, most of my sites don’t use it.
So, to do enable this, it’s simple, especially on a Windows install.
Simply open your php.ini file [ should be located on your server somewhere similar to c://program files/php/php.ini ] and edit the line:
;extension=php_mbstring.dll
and change it to
extension=php_mbstring.dll
For me, this was on line 676 of my install [php.ini file].
I should note that during the fresh install of PHP, using the windows installer, there is an option to enable different libraries. I have, however, had trouble in the past re-running that install (*.exe) so I choose not to re-run the install to activate this library. I have also never tried enabling it upon install, maybe some of you have and it works fine?
Oh, and after this is changed, and saved, remember to restart Apache!
Good luck!