Upload Theme - Error

I have installed Wordpress and XAMPP as a localhost. I have purchased a theme and when I upload theme from the zip file provided i get the following error.

POST Content-Length of 15342756 bytes exceeds the limit of 8388608 bytes in Unknown on line 0

Can someone please help.

Your php is running out of memory. You can increase the amount of memory allocated to php and it should fix the issue.

http://docs.themewich.com/article/78-increasing-the-wordpress-memory-limit