Look for the following php.ini files in your apache and php folders look for upload_max_filesize and post_max_size and change the default values.
C:\wamp\bin\apache\apache2.4.9\bin\php.ini
upload_max_filesize = 64M
post_max_size = 10M
or
C:\wamp\bin\php\php5.5.12\php.ini
upload_max_filesize = 64M
post_max_size = 10M