Cannot load mysql extension. Please check your PHP configuration

I installed AppServ 2.5.10 in my Windows 8 notebook, php and mysql were working fine in the beginning. I then commented  out  skip_innodb  in my.ini  and then phpMyAdmin doesn't work  and came with error message  "Cannot load mysql extension. Please check your PHP configuration" .  PHP is working fine but I cannot load mysql.

I try to uninstall and re-install the same package but it still doesn't work.

I appreciate any clue to solve this problem. 

Thanks.