Transfer license when updrading to Windows 10

[physicsboy]

Getting ready to upgrade a Win8.1 box to Win10 - Not an in-place upgrade, a fresh install to get rid of lots of crap that accumulated over the past year. How do I transfer my exist license Avast Pro 2015 after I do the fresh OS install?  My current license is good through 1/2016 and I don't want to lose the months I've paid for.

Thanks, Steve

[Lisandro]

You can register for an Avast account and store it there, adding the "new" computer and removing the old one.
You can also save your license file (received by email) and restore it later or even get your already paid license: http://www.avast.com/resend-license-paid.php