I think the answer of LIVIA LOPES is very good, though I don't have any idea of this ERP. As far as I know that an ERP is very costly to implement at a business like cyber cafe, unless it's spread business.
For a single cyber cafe, it is useful to make a access database (with both front and back end use), where the software have option for"
1. Name
2. Address
3. Contact No.
4. Type of ID Card
5. Number of the ID Card.
Whenever a user want to use a particular computer, a LOGIN key passed by the administrator and mention the time the user want to use. As soon as the administrator press the login key, it will display an window on the particular computer (each computer have specific name) for filling up above 5 details by the user. After complete the form only the user can use the computer.