Go to your xampp install directory ->apache/bin, there you should have php.ini file.
find this line:
;extension=php_memcache.dll
and replace it with:
extension=php_memcache.dll

now download memcached from here

Now you have to install memcache as a standalone service:

a)Unzip and copy the binaries to your desired directory (eg. c:\memcached) [you should see: memcached.exe and msvcr71.dll]
b)Install the service using the command: c:\memcached\memcached.exe -d install from the command line
c)Start the server from the Microsoft Management Console or by running one of the following commands: c:\memcached\memcached.exe -d start, or net start “memcached Server”

3.Now you have to test it to see if everything’s allright:

Using Memcached with MySQL and PHP

thats all