RegQueryValueEx

I am trying to read information from the registry using [RegQueryValueEx]. I am getting error numbers, but I don't know what they mean how can I find out what they mean and what I am doing wrong?

I don't know what operating system you are using
but if your RegOpenKeyEx returns non error
All parameters most be fill for Windows 95 but not with NULL or "".

Same as de first reply, for the number error see "winerror.h"

If you want to see the system message that corresponds to the return value, use the FormatMessage function. Make sure you use the FORMAT_MESSAGE_FROM_SYSTEM flag. This is a standard API call that is pretty useful if you need to display the same error message Windows would.