This rule is a calculate rule. So you would go into Data Translation Services, go to the Calculate Data node, All Rules and right click on Computer.Barcode. Then you would select Set Active. It will ask you if you want to run the rule now, say Yes to this so it sets up the barcodes immediately for the computers in the database. Then you need to make sure that the scan interruption is enabled. You should see at the end of the DTS toolbar, a little (very little) stoplight, it should be green. If it is red, click on it and Enable Real Time Scanning.