Any supposed "free" site that asks for payment before they pay you is a scam. If you work for someone they won't ask you to send them money before they pay you.
In fact referral systems promising to pay you for nothing esp in naira are usually scam.

@skydancer. Please my laptop comes on but when it shows the mouse it hangs. Please what should I do? I think the hard disk is corrupt, what should I do if. That is the case?