Hide Data from access by users (Win)

We are looking for someone who knows how to hide data from access by users. Background: We have an trial function in our software. The startdates will stored inside the registry. This is an very unsecure way. Sure, everything is encrypted but the problem is the values are deletable. Now we want to find an solutions to store this data at an place where noone can read this data, only our software. We need to store an encrypted string. The need of write and read is a must. Technology: We are open to discuss everything. But nothing that will look like an virus or malware. Please give us your ideas and your experience. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform Windows