Here's a routine I run that tries to get the info from the Windows API. If it fails, it then tries the FoxPro information.

* Declare the API function.
DECLARE INTEGER GetUserName IN Win32API STRING @S, INTEGER @I

* Define the buffer size and destination variable.
lnDWord = 20
lcBuffer = SPACE(m.lnDWord + 1)	&& One for the trailing NULL

* Try the API function.
IF (GetUserName(@m.lcBuffer, m.lnDWord) = 1)
	* Use the API call results.
	lcUserID = STRTRAN(ALLTRIM(m.lcBuffer), CHR(0), [])
ELSE
	* Use the FoxPro function.
	lcUserID = ID()
ENDIF