Thanks for your reply. Perhaps the DEMO version does not run on .Exee. or maybe I'm missing include some instruction. or maybe I downloaded an incomplete or unauthorized DEMO copy from a website. I have really only two days working with this library. and I have new questions :
1 .- Where I can buy the Cryptor 5.0
2 .- version 5.00.124 is the last version released? or are there new versions?
3 .- which companies provide technical support of Crytor?

I think the most suitable solution to protect the tables .dbf is using Crptor. only in case of failing to get a supplier who can sell me cryptor with tech support I'll buy the software UniversalShiel 4.3.1.

Thanks again !