THE FOLLOWING WORKED FOR ME!!!
1) Download PHP64 version from this link (http://icrontic.com/forum/showthread.php?t=46956)
2) Extract main zip file and find another file “php-5.2.5-x64-2007-11-12.zip”
2) Extract “php-5.2.5-x64-2007-11-12.zip” and copy the contents of “php-5.2.5 (x64)” into C:\Phpx64\
3) Pint your web services extension to C:\Phpx64\php5isapi.dll
4) Go to properties of ” Web Sites” Directory in IIS and then into HOME DIRECTORY ->CONFIGURATION -> Add or edit .php extension here. You would need to point to the same dll “C:\Phpx64\php5isapi.dll”
ALL DONE!