There muse be a proper way of doing this, but I can't see it.
In case you or someone feels like trying it these are the steps to make this a macro in Word 2003. I wouldn't blame you for waiting for an easier way
Open Word but close all documents. You don't even want a blank one open.
On Tools Menu there is a submenu called Macro and on that I have 'Visual Basic Editor' which I click.
Then on the Insert Menu select 'Module' and a little box opens. Paste the lines below into the box. then on the File menu click 'Save Normal'
Close everything and open a document with pictures in. Go to Tools - Macros and click the Macro option. You should see Resize Pics as an option.
Do not experiment with your only copy.
Dim xSize As Integer
Dim ySize As Integer
Public Sub ResizePics()
xSize = InputBox("Enter width", "Resize Picture", 75)
ySize = InputBox("Enter height", "Resize Picture", 75)
Dim oDoc As Document, oShape As InlineShape
Set oDoc = Application.ActiveDocument
For Each oShape In oDoc.InlineShapes
oShape.Height = ySize
oShape.Width = xSize
Next oShape
Set oDoc = Nothing
End Sub