I'm trying to write a script in php that requires imap functions. I found the functions at here. How do I download and install it in windows ?
No - the link you provided is the documentation for the functions.
I guess you are on a Microsoft Windows platform since you've tagged your question with 'windows' even though its nothing to do with GUIs or data window algorithms (in future it might be a good idea to be a bit more explicit, particularly when talking about installing software).
The imap extension comes as standard with the MSWindows PHP installation. You just need to enable it in your php.ini
Run
To find out what ini file your installation is using. The default php.ini should already contain a line to load the extension but commented out:
;extension=php_imap.dll
Change this to (or add):
extension=php_imap.dll
Note that if you are running php within a webserver or as fastcgi, you'll need to restart it for the change to take effect.
C.