The Solution: I changed the Read Only attribute in the file for "tp_editor" (Modified By) back to "TRUE".
For my own purposes I won't ever need to programmatically alter the Modified By field (I know, then why did I change it in the first place?
When in details view right click on the date showing above the dialog box to pull down the the options and uncheck or check to turn on and off types of date attributed to the files.
I usually just turn on date modified so I always know when a files was touched or worked on by someone!
But for anyone else who may run into this in the future, here is a more detailed explanation of what it did, why i did it, what problem it caused and what the solution was: What I did: In the Sharepoint directory: "\Program Files\Common Files\Microsoft Shared\web server extensions\TEMPLATE\GLOBAL\XML\" there is a file called ONET.xml, this xml file controls properties for standard, managed columns across a Sharepoint farm (Title, Attachments, Created By, Modified By, etc.) the Created By and Modified By columns are referenced internally as "tp_author" and "tp_editor".
For both of these, i changed the Read Only attribute in the xml from "TRUE" to "FALSE" Why I did it: I had a list that i wanted to alter the Created By field with a Workflow that would run each time an item was created.
(this gave us the ability to operate the list with "Only their own" permissions, as we dont want users to see anything but their own items, while Admin can make changes to any item on the entire list. there's nothing wrong with my MOSS 2007 installation from what i can tell, everyhting is working exactly as expected.except: no list on any site in MOSS updates the Modfied By field.Thanks Not sure about other Windows versions but in Win 7, 'Date Modified' does not show the date it was modified in Sharepoint 2010.In Windows Explorer, right click the header and choose 'Date last saved', which will show the Sharepoint last modified date.The Problem it Caused: What I discovered was that by changing the Read Only attribute from "TRUE" to "FALSE", the Modified By field would not update with the last person that updated the item, which prevented us from being able to identify a clerical error and know who made the mistake.For our purposes we don't care who originaly created the item, we only care who last edited or updated the item.So when a file is copied into Share Point, the date modified column is updated in SP but the date modified property of the file itself is not updated because the file hasn't actually changed it's contents.There are 3 types of date attributed to a file, the date created, the date accessed (only shows in properties dialog box I believe) and the modified date.Why is the explorer view different, and can we correct it?The explorer view is looking at the date modified property of the file and not the sharepoint date modified column.