Your search SQL will look something like this example, assuming the textbox is called txtSearch:
Code:
SELECT *
FROM Parts
WHERE ( (PartNo like "'*" & Me.txtSearch & "*'")
OR (PartNo like "'*" & Me.txtSearch & "*'")
OR (Description like "'*" & Me.txtSearch & "*'")
OR (ExtDescription like "'*" & Me.txtSearch & "*'")
OR (Machine like "'*" & Me.txtSearch & "*'"));
That code will not run as is - you'll have to adapt it to how you are doing the search, for example if it's in a control filter, you'll have to drop the "WHERE" and change around all the quotes as needed, or if it's in a stored query you'd probably want to use a temp variable to store the search string value of "'*" & Me.txtSearch & "*'".