Paste this code into the VBA Explorer and change the path on line 4 to point to the folder containing the files (make sure to include the trailing slash).
This will search all rows and columns. If there are other instances of the search string in different columns than C, it will return those too. It can be modified to only search a single column range but would no longer work if the range changed for some reason.
Dim myDir As String, fn As String, ws As Worksheet, r As Range
Dim a(), n As Long, x As Long, myTask As String, ff As String, temp
myDir = "C:\test\" '<- change path to folder with files to search
If Dir(myDir, 16) = "" Then
MsgBox "No such folder path", 64, myDir
myTask = InputBox("Enter Customer Name")
If myTask = "" Then Exit Sub
x = Columns.Count
fn = Dir(myDir & "*.xls*")
.ScreenUpdating = False
.EnableEvents = False
Do While fn <> ""
With Workbooks.Open(myDir & fn, 0)
For Each ws In .Worksheets
Set r = ws.Cells.Find(myTask, , , 1)
If Not r Is Nothing Then
ff = r.Address
n = n + 1
temp = r.EntireRow.Value
ReDim Preserve temp(1 To 1, 1 To x)
ReDim Preserve a(1 To n)
a(n) = temp
Set r = ws.Cells.FindNext(r)
Loop While ff <> r.Address
fn = Dir
If n > 0 Then
.Resize(n).Value = _
MsgBox "Not found", , myTask
Note: this was tested on Excel 2010, but should run fine on 2007. Modified code from this source.