This is for anyone that has purchased a single license or license package for Blink Personal Edition.
To save yourself the headache of dealing with the error message "This license has already been used", follow these steps if you intend to un-install Blink (before re-installing it) or you have to re-image or re-install your Windows OS for any given reason.
From Blink's Help menu at the top complete the following steps:
1. Go to "License Management"
2. Select the circle next to "Transfer License"
3. Click Next
4. Select the box at the bottom of the next screen that says "Yes, I want to remove my license from this machine."
5. Click Next and acknowledge any further prompts.
This should save you from going through any license related issues which will require you to contact eEye to have your license reset.
If your unable to complete the steps above, follow the steps given in this forum post for releasing your license:
http://forums.eeye.com/forums/p/992/4313.aspx#4313