Whatever be the reasons, if you want to delete your Hi5 account and can’t figure out how to do so, then this is the procedure:
Step 1: Login to your Hi5 account
Step 2: click on the Account link in the Homepage
(A tiny link at the right-hand side of the header, just below your account user name)
Step 3: Click on the button that says “Cancel my account“
(situated on the right side of the page).
Step 4: Think final time, if still convinced to delete your hi5 account; fill-in the asked information and make a final click on the "Cancl my Account" button.
Your Hi5 Account deleted.
*** For those who still found this article insufficient, Try this it'll take you straight to the final step :
Go to this page.