Changing the Duration Associated with SharePoint’s “!New” Indicator

To turn off the “!New” icon, set the number of days to zero
The change is for ALL list items (not just documents) on the virtual server
The change is immediate and does not require an IISRESET
More information is at the following KB article…
http://support.microsoft.com/default.aspx?scid=kb;en-us;825510&Product=spts
Run the following (you may need to navigate to the directory where stsadm resides):

stsadm.exe -o setproperty -pn days-to-show-new-icon -pv ## -url [Your Virtual Server’s URL]

where ## is the number of days to show the “!New“ icon