Hi all, I need to enter a value in HKLM\CurrentControlSet\Enum\<device-type>\<vendor-id>\<sub-value> key (I want to load a filter driver for a device using my program, so I need to add a LowerFilters entry here). I'm using RegSetValueEx() but it is returning error 5. AFAIR this is for ERROR_ACCESS_DENIED. I can enable write permission on the key from regedt32, but I want to implement this in my program. How do I get the permission? I'm assuming I have to use RegSetKeySecurity() but I'm new to windows security and am confused with the 2nd and 3rd parameter. Any suggestions/pointers any1? Thanks in advance.