VB - making API calls

[ASK]

I am using API calls which modify Registry with the following functions,
RegSetValueEx,
RegQueryValueEx,
RegOpenKeyEx,
RegCloseKey
I am working on VB 6.0 in 95 platform and the program works fine.
When I run the exe on Windows NT i can open the key and view the values but not update the values.

Can anybody help me. My project is stuck up because of this.

[Lothar Haensler]

make sure you specify the correct value for the samDesired in your RegOpenKeyEx call (KEY_WRITE).
Also, check the return code of all API calls and call FormatMessage to get a readable explanation of the error.