7-Zip is a free software. However, you can support development of 7-Zip by registering and paying $20.
As registered user, you will be able to get technical support via e-mail support@7-zip.org.
Register 7-Zip NowYou can find all information about registering and about types of licenses at:
http://www.7-zip.org/register.html
Thank you very much in advance!