Help - filexist on lan

[Hairy]

I have 4 pc's connected on a simple lan, thru a hub.
If I find them on network neighbourhood and map the three computers as drives M, N & O. What is the best way to see if the computer is connected and not been turned off as I need to access databases on their hard disks. The databases are all called the same in similar directories on each machine. If I use the DIR function to see if VB can see the file it is ok until the machine is turned off then it starts acting weird and comes uo with error messages......
PLEASE HELP ;-)

[chenko]

check if the file exists

Public Function FileExists(FileName As String) As Boolean
    If Dir(FileName) = "" Then
        FileExists = False
    Else
        FileExists = True
    End If
End Function

[plenderj]

or snappier :

Public Function FileExists(FileName As String) As Boolean
    FileExists = Dir(FileName) <> ""
End Function