Wednesday, 8 February 2012

Missing in action

No not me (although I have been missing for some time!) I’m talking about the registry key

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Url History\DaysToKeep

For those of us looking at dead boxes this key can be found within each users NTUSER.dat registry file and is used to record how many days history Internet Explorer keeps for the particular user.  As many of us know the default is 20 days.  In a recent case the value of this key was pertinent and when I went to examine it on two separate boxes I found it was missing.

For the record one box was running IE8 on Windows 7, the other IE6 on XP.  I also checked out a test VM of mine running IE7 on Vista for good measure and the key was missing on that box also.

So after a little bit of testing I have established that this key is only created if the user visits the settings dialogue shown below in Figure 1.  If the user does not visit this dialogue since the browser’s installation (or for that matter after the deletion of the registry key) the registry key is not created.  Once this dialogue is visited the registry key is created whether or not the days to keep setting is actually changed.


Figure 1

It has been suggested to me that in the absence of the registry key detailed above the registry key

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Url History\DaysToKeep

takes over (found in the SOFTWARE registry file on a dead box).  In my testing this key could be edited to another value instead of the default 20 days and the days to keep listed in the settings in Figure 1 would remain at 20 days.  This obviously begs the question what is this key for.  As far as I can ascertain it is possible to set a group policy to enable a per machine (as opposed to a per user) setting and in that case this key takes effect.

Until next time.

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