VFP registry class can handle only string values. You can download registry class from http://west-wind.com/wwvfppd.htm that works integer values also.

? oReg.ReadRegistryInt(HKEY_CURRENT_USER, ;
         "Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced", ;
         "HideFileExt")

>Thanks, Sergey. Maybe you could help me further: I am getting an error -106 : "data type for value is not a data string".
>
>I see in the registry the HideFileExt type is REG_DWORD.
>
>My code is:
>
>SET proc to HOME()+"samples\classes\registry.prg"
>o=CREATEOBJECT("registry")
>? TRANSFORM(o.getregkey("HideFileExt", @cValue, "Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced", HKEY_CURRENT_USER)