Windows XP and DNS

DNS or Directory Name Service is how your browser finds a website from a name.  For example when you type in your browser looks it up on a DNS server and gets the correct address and then opens the page for you using that address.   It would be like asking where the local pub is and someone telling you it is on 712 Main Street so you can then can go to that specific address.

Most DNS servers today update their information every 2 hours and sometimes even less.  However when XP was around the servers only updated every 24 hours or more.  If you are still running XP you can change this value with a registry edit.  This edit works on newer systems as well but most current operating systems take the shorter time into account.

The registry edit is as follows:


HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\ Services\Dnscache\Parameters
Add the DWORD value: MaxCacheTtl

then set the value (in decimal) to:  7200

That sets it to expire entries that are 2 hours or older.

Another thing that DNS does is cache negative entries.  These are simply entries that did not resolve to a legitimate address.   If you use multiple DNS providers or are checking to see when a site comes up after setting it’s DNS this could also be useful.  To do this there is another registry setting you can put in.


The registry edit is as follows:


HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\ Services\Dnscache\Parameters
Add the DWORD value: MaxNegativeCacheTtl

then set the value (in decimal) to:  0

This will tell XP to stop caching stuff that’s not there.

After you have applied either or both of these registry settings you can reset the DNS cache on your computer by opening the command prompt and typing the following:

ipconfig /flushdns

Your computer should return:

“Windows IP Configuration

Successfully flushed the DNS Resolver Cache.”


If you are running a desktop computer you probably never put it into a hibernate mode.  Sleep is usually good enough since it does not have a battery to drain and computers wake up from sleep faster.

There is a file that is created on your computer made for hibernation that will completely save your desktop state called hiberfil.sys.    This file is hidden and on the root directory of your hard disk.   It contains everything you need to wake up from sleep.  However this file is not necessary if you never hibernate your computer and most desktops do not need hibernate mode.

Microsoft has more information on this as well as the means of turning if off and on.  It is on their website under Knowledge Base Article 920730.  Or if you want to just do it your self you can open the command prompt in administrator mode and type the following command:

powercfg -h off

If you want to turn it back on for any reason just use the same command with the word “on” instead of “off”.

Security Alert for Windows

If you have Quicktime for Windows installed now is a good time to un-install it.  Apple has discontinued support for the Windows version of Quicktime and will not be issuing updated for security patches for current or future security problems.

Homeland Security has issued a warning about this as well.  You can read the article here.

Enable the F8 restore key at boot in Windows 10.

Sometimes we have a need to fix something we broke and the only way of doing that is to roll back to a previous version.  Up to Windows 10 you were able to press the F8 key while the operating system was just starting up and then choose restore to last known good configuration or even pick a previous date to restore from.   In Windows 10, however, they have elected to disable this feature in favor of a faster boot time.   While a faster boot is usually more desirable there is also something to be said about being able to restore in case you mess up.

If you wish to restore the F8 while booting, you can just use a simple command.   Don’t worry this command can be reversed.   If your system hangs before you do this, you will need to get a Windows 10 boot disk to repair the error.

You want to go to a command prompt with administrator rights first.  Use the search and type cmd, right click on command prompt and select “run as administrator”.   Once in the command prompt use the command:

bcdedit /set {default} bootmenupolicy legacy

you should see “The operation completed successfully.”  And that is all there is to it.  If you wish to undo this, then open the command prompt as administrator and use the command:

bcdedit /set {default} bootmenupolicy standard



Clear the Windows Paging File at Shutdown

First off, why is this important?   The paging file is a cache of information that is offloaded from your system when it needs to move stuff around.  This can be both programs and data.  The important part here is that it can be data.  Normally you don’t need to worry about this and as you turn off and on your computer it automatically handles all of this information.   The paging file has been tweaked and modified over the years and functions very efficiently with all the Windows defaults.   The one problem that it can cause is for people who deal with sensitive information.  While the defaults work great it still retains information when you shut down your computer.   So if your information requires you to do things like clearing cache and history then you are missing something if you do not also clear the paging file.

This fix will help with security but, as with anything like this, the drawback is that it slows down the shutdown process.  This is due to the fact that it needs to perform the clearing of the paging file before it shuts down.

If you want the quick fix you can go to Microsofts Fix It.  (it appears that the Fix It solution is no longer available).  Or, if you are a do it yourselfer, here is the registry edit:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\

ClearPageFileAtShutdown = 1

If the ClearPageFileAtShutdown does not exist create it using DWORD 32Bit).

If you want to set it not to clear the paging file, then you can just change the value to 0.