Russell-

>I would like to populate a list with the drive letters of availble disk drives and shared drives. Is there a way to do this?

You have two possibilities, and George has pointed you to a third. For example,

LOCAL lnBuffSize, lcString, lnDrives, lni
lnBuffSize = 200
lcString = SPACE(lnBuffSize)

DECLARE INTEGER GetLogicalDriveStrings IN Win32API AS GetIt;
	INTEGER lnBuffSize, STRING  lcString

= GetIt(lnBuffSize,@lcString)

lnDrives = OCCURS( ":", lcString)

FOR  lni = 1 TO  lnDrives
	THIS.ADDITEM(ADDBS(SUBSTR(lcString, AT(":",lcString,lni )-1,2)))
ENDFOR

I just want to warn you that in any of these cases, if a mapped drive hasn't been connected yet, none of these methods will find them. This is a "gotcha" I ran into when I made a backup routine for a client.