From a previous post.

That is exactly what we use it for, dev and prod.


What problem exactly are you getting with the SetEnvironmentVariable API? Is
it that trying to read it with Environ in the same NT/XP session does return
a value? If that is the case, I think this is because Excel seems to load
the environment variables at start-up, and Environ gets the values locally.
So any changes that you make are not reflected in Environ. And as
SetEnvironmentVariable only sets the variable for the current session, this
stymies you.


You can get around it though by using GetEnvironmentVariable to read it as
this will read any variables in the current session. This code snippet
should demonstrate it, GetEnvironmentVariable returns the newly set value,
Environ doesn't


Option Explicit


Private Declare Function GetEnvironmentVariable Lib "kernel32" _
Alias "GetEnvironmentVariableA" _
(ByVal lpName As String, _
ByVal lpBuffer As String, _
ByVal nSize As Long) As Long


Private Declare Function SetEnvironmentVariable Lib "kernel32" _
Alias "SetEnvironmentVariableA" _
(ByVal lpName As String, _
ByVal lpValue As String) As Long


Sub xx()
SetEnvironmentVariable "Rob", "Nuzie!"
MsgBox Environ("Rob")
MsgBox GetEnvironmentVar("Rob")
End Sub


Function GetEnvironmentVar(Name As String) As String
GetEnvironmentVar = String(255, 0)
GetEnvironmentVariable Name, GetEnvironmentVar, Len(GetEnvironmentVar)
GetEnvironmentVar = TrimNull(GetEnvironmentVar)
End Function


Private Function TrimNull(item As String)
Dim iPos As Long
iPos = InStr(item, vbNullChar)
TrimNull = IIf(iPos 0, Left$(item, iPos - 1), item)
End Function


--
HTH

Bob Phillips

(remove nothere from email address if mailing direct)

"Ken Soenen" wrote in message
...
Is there any way to set a Window's Environment variable from within Visual
Basic Code. I know I can read one via the VB Environ.

thanks,
ken