manuadminmod help installation

hey guys
i have a problem installing the mod
in part 4 in the installation guide they say
There replace "[PATH_TO_PHP]" with the patch to your EXE of your PHP-Installation (for example "C:\php\php.exe" - without quotes!). Exit and save the changes.
i replace the path for what EXE ? what is PHP installation ?

thanx but i have another problem now
when i replaced the path of the php when i press save [ctrl+s]
it shows me to save as a text file and i cant save it to the folder
any suggestions

//EDIT 1:

i tried now with wordpad they tell me when i try to save acess is denied
any help

//EDIT 2:

and in the office word it says when i try to save it says the document is read only.enable write permissions