ERPlite uses encrypted Sitekeys to enable the software and options. Through this mechanism, the same copy of ERPlite can be enabled from 30 days up to unlimited time. As, well optional modules, like MRPlite:LS, can be disabled if the customer does not wish to buy the option. ERPlite is downloaded with a Sitekey that disables all software except the authorization module. The authorization module writes a unique digital signature on your PC's hard disk and computes a unique encrypted SiteCode. You email this SiteCode to support@erplite.com. Support computes an encrypted SiteKey enabling the agreed to options (everything enabled for 30 days is the default). Support then emails you this unique Sitekey. You copy and paste it into ERPlite, and complete the authorization process, thus enabling your version of ERPlite.