How do i open .ini and .php files, (also, if i use runescape.com's source

[My name is- Trousersnake]

code, can i use in php? Hi, i use HTML files but i want to try something new, so i downloaded PHP and now i cant open it (i can edit it but i want to open it to see what ive done) It says it cant find the program to use, do i just use internet Explorer or what, Thanks
If it is internet explorer, i just open it, window pops up, goes away, and repeats