>I created an application that uses the _cryptapi routines to encrypt/decrypt file names. I have tested in W98 & W2000 environments and everything works just fine. However, if the program is installed on an XP machine, the application doesn't see (decrypt?) the file names. Has anyone out there had any experience with _cryptapi and Windows XP? I'm confused where I should look for the problem. This is a VFP7.0 program compiled on a W98 machine. Are the WIN32API's/calls different? When running, the program doesn't crash or error like I would think it should if I missed a parameter or something, it just doesn't appear to recognize my encrypted file names under XP.

There was a change in the Cryptographic Services Providers. Make sure your CSP is the same.
Look in Wincrypt.h:

#DEFINE dsMS_DEF_PROV_A       "Microsoft Base Cryptographic Provider v1.0"

HTH