Blue Screen of Death keycrypt64.sys

Symptoms: Computer is an HP Model that suddenly blue screens and returns an error with keycrypt64.sys before rebooting.

Items Needed: USB Mouse, USB Keyboard, Windows Boot Disk or Utility Disk

Solution: A recent update push to Constant Guard (Comcast) has a conflict with the default keyboard / mouse dll for HP Machines. This is a temporary fix.

Step 1. Boot the machine using the utility boot disk to access a command prompt.

Step 2. Copy C:\windows\system32\drivers\hpqkbfiltr.sys to C:\windows\system32\drivers\hpqkbfiltr.old (THIS WILL DISABLE YOUR KEYBOARD AND MOUSE THAT ARE NOT USB)

Step 3. Attach the USB Keyboard and Mouse plugged into a side port and reboot the laptop. Windows should boot normally.

Step 4. Once logged into windows, go to control panel, add/remove programs and remove Comcast Constant Guard

Step 5.  Reboot and use the USB Keyboard and mouse to rename C:\windows\system32\drivers\hpqkbfiltr.old to C:\windows\system32\drivers\hpqkbfiltr.sys

Step 6. Reboot, unplug USB Keyboard and Mouse, computer should be running fine..

Special Thanks to Bob Bailey for posting this solution for the community!

4 thoughts on “Blue Screen of Death keycrypt64.sys

  1. Hey, thanks for the information! I ran into this issue for a client today and got them back working pretty quickly using a Hiren’s Boot CD to access and rename the .sys file mentioned above.

    Unrelated, I created a post on my site linking back to yours. However I noticed afterwards that in the top left corner of your website, there is a link to “best online casino” ( Is this intentional on your part? If not, I simply wanted to post a heads up to the added link in your code!

    Best regards,


    • Jason,

      Thanks for the heads up, looks like it was a plugin from the wordpress site that was replicating the link. Thank you for pointing it out.


  2. Thanks for this info. You were the first result when I did a Google search for “disable keycrypt64.sys” and everything worked great.

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