Novice related issue: mysqli extension not found on WIN7

Novice issue: WIN7 cannot find the mysqli extension
Little Brother Beginner PHP,
WIN7, an error occurred while logging in to phpMyAdmin: missing mysqli extension. When you call Mysqli_connect in a PHP script, you get an error:
Fatal error:call to undefined function mysqli_connect () with XXXX on line xxxx
Should this be the case that the extension is not found? But I have opened the Extension=php_mysql.dll and Extension=php_mysqli.dll, the two DLL in the directory is also added to the environment variable, but still not.
It is strange that I can run successfully under the same environment as XP. What's going on here? Ask.
My environment: Operating system WIN7 flagship version, PHP version 5.2.17, Apache 2.0,mysql version 5.5.29 extension PHP phpMyAdmin Extended

------Solution--------------------
I also met this problem, I solved it yesterday.

Copy the Libmysql.dll and php.ini two files to the C:/windows directory,
If not, copy it to the C:/windows/system32 directory.


------Solution--------------------
In this case, you should write in Apache http.conf.
SETENV PHPRC "Path/php5/"
Phpinidir "Path/php5/php.ini"

You should also set the extended storage path in the php.ini.
So you don't have to copy to the win directory.

Reference:

I also encountered this problem, I solved yesterday.

Copy the Libmysql.dll and php.ini two files to the C:/windows directory,
If not, copy it to the C:/windows/system32 directory.

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