From Zapper Software:
This program is for software developers who want to protect their software and create 30-day trial ware. This is a software copy protection system. ShareGuard consists of 4 components: ShareGuard Lock, ShareGuard Key, ShareGuard Locksmith, and CRC Check. ShareGuard works with any Windows programming language (Visual Basic, MS Access, C++, Delphi, VB.NET, and C#). It allows for several types of key generation and supports software leasing and EXE wrapping. ShareGuard will lock and unlock an unlimited number of customers for all of your products royalty-free.