If you no longer wish to use VS, you can disable your volunteer account.
To disable your account:
Log in to your volunteer account (see Logging in to Your Volunteer Account for instructions, if needed).
Click the Your Account link at the top of the page.
In the Profile Administration section of the Account Manager page, click the Disable your account link.
On the Disable Account page, select one of the two options for disabling your account.
Click Yes, I am sure. Note that this will log you out of VS and you will not be able to log back in.
Registering/Creating a Volunteer Account
Logging in to Your Volunteer Account
Updating Your Volunteer Account