Q1 : UPDATE - How do I update Guitar Pro 6? Do I need to pay again? 
The Updater integrated into the software will automatically take care of the updates for v6.x.
If your computer is off-line, please find a detailed guide
here.
As a registered version 6 customer, you are entitled to free updates to 6.x.
Just as well, you can download the software again, free of charge, is you move to another platform (Linux, Windows, or Mac OS); and activate it up to 5 times over a one-year period (cf. license agreement).
To download a new copy of the software, please go to the
Customer Area of our Support section.
Q2 : UPGRADE - I have Guitar Pro 3, 4, or 5, do I have to pay for the 6th version? How do I get the upgrade? 
You still need to buy the new version (contrary to the updates within a given version, which are free). However, you will get a 50% discount for the 6th version if you already have a licence for Guitar Pro 4 or 5.
Click here to go to our purchase page and get the price of the upgrade.
Please just indicate your USER ID and KEY ID on the
order form (step 1, section 4).
NB : The discount is not available is you only own version 1, 2, or 3.
Q3 : UPGRADE - Do I need to have Guitar Pro 5 already installed on my computer to order the upgrade to GP6? 
NO. You just need your version 5 (or version 4) license information to order an upgrade. Please just indicate your USER ID and KEY ID on the
order form (step 1, section 4).
Q4 : LICENSE - What if the system does not recognize my USER ID and KEY ID? 
First make sure that you have correctly entered your USER ID and KEY ID (for instance, do not type "1nt" for "int", and respect the format XXXXX-XXXXX-XXXXX for the Key ID).
We recommend you use the
license-recovery form to check your license numbers.
Click here to find a detailed installation / activation guide, and see how to achieve off-line activation.
If you are sure you have made no mistake, or in case the e-mail address you used when you registered your license isn't active any more, do
contact us directly. Please make sure you give us your full name and postal address at the time of your purchase/registration of Guitar Pro, so we can retrieve your file from our database.