Searching For File On All Drives

The Code below searches for a file and displays how many files by that name it found.

Sub Test()
With Application.FileSearch
.NewSearch
.LookIn = "C:"
.SearchSubFolders = True

.Filename = "Temp.txt"

If .Execute > 0 Then
MsgBox ("Success: " & .FoundFiles.Count)
Else
MsgBox ("Fail")
End If
End With
End Sub

However, Flashdrives are a common use among those that will use the code, such that I need the code to not only search the hard drive C: but all hard drives and flash drives. Using .Lookin = My Computer did not find the files stored on my Flash Drive.
It finds it using .Lookin = "K:" but I can not rely on my flash drive always being K:. It does not find it using .Lookin = "PumaFlash" (Name of flash drive)

I'm looking for one of two things: Code that will Search all hard drives and flash drives (optical drives can be included) at once Code that will Find path for all hard drives and Flash drives and then search them separately