How to restrict users to create only one account from a single machine on rating website
I am working on a website development of rating site. 

***How can I restrict users not create another account from the same pc?***

**Explanation:**

For example, user register to my site and can post reviews and rate to some product. But i don't want him/her to continuously review and rate the same product again and again to avoid this; i restrict users to post only limited reviews or some think like that....(this is done)

The problem is, possibility of user can create another account from the same pc, in this way he/she can create multiple accounts... and post reviews & rate the same product. For this issue I want some mechanism to gather some unchangeable info of the user-PC so if he/she try to create another account i.e. THIS PC is already registered with another account.

There are some site of rating which provides this security for illegal reviews and rating... i think of MAC ADDRESS but its not the right way i found!! so far


How to restrict users to create only one account from a single machine on rating website
===

I am working on a website development of rating site. 

***How can I restrict users not create another account from the same pc?***

**Explanation:**

For example, user register to my site and can post reviews and rate to some product. But i don't want him/her to continuously review and rate the same product again and again to avoid this; i restrict users to post only limited reviews or some think like that....(this is done)

The problem is, possibility of user can create another account from the same pc, in this way he/she can create multiple accounts... and post reviews & rate the same product. For this issue I want some mechanism to gather some unchangeable info of the user-PC so if he/she try to create another account i.e. THIS PC is already registered with another account.

There are some site of rating which provides this security for illegal reviews and rating... i think of MAC ADDRESS but its not the right way i found!! so far

