I have a Dell Inspiron 15 5547 Laptop running Windows 8.1 Pro. I encrypted the device with Bitlocker. When the machine boots to the Bitlocker login window the keyboard stops working. Sometimes I can't type anything and other times I can type anywhere from a couple to several characters before it stops working. Every great once in awhile I have enough time to type in the key before it stops.

Troubleshooting I've tried:

-Updated all drivers and BIOS to most recent

-Opened up the laptop to check the keyboard connection internally

I can plug a USB keyboard into the machine and it works every time with zero failures. Any ideas?

Hi DericM,

"I can plug a USB keyboard into the machine and it works every time with zero failures."
Do you mean the issue only occur with the onboard keyboard?Have you tried to manually check for updates for the machine to ensure it has got the latest updates?
Did the keyboard work well with bitlocker before?Have you tried to reinstall the device to have a check(It is recommended to download the latest driver from the manufacturer website for the device)?
Uninstall or Reinstall a Device
https://technet.microsoft.com/en-us/library/cc725782.aspx?f=255&MSPPError=-2147217396

To rule out the third party service conflict issue,we can perform a clean boot to have a check.
How to perform a clean boot in Windows
https://support.microsoft.com/en-us/kb/929135

If this keyboard never worked with the bitlocker,there may be a compatible issue here.We can try to ask for help from the Dell forum for help at the same time.
Here is a similar symptom for reference:
Bitlocker issue with Dell Inspiron 5000 series keyboard
http://techdenovo.blogspot.com/2014/10/bitlocker-issue-with-dell-inspiron-5000.html

NOTE: This response contains a reference to a third party World Wide Web site. Microsoft is providing this information as a convenience to you. Microsoft does not control these sites and has not tested any software or information found on these sites.

Best r