Unknown Device
In the Other Devices section in Windows 7 Device Manager it may show an error as an Unknown Device. Details on the device will show ACPI\MSFT0101 (Figure 1, English only).
Windows 7 Device Manager
Figure 1
This device corresponds to the TPM module which does not have a driver available for download on dell.com, but can be installed easily using Windows by following the steps outlined below.
Solution- steps to resolve the issue
- Right-click the Unknown device and click Properties.
- On the General tab, select Update Driver…
- Click Browse my computer for driver software (Figure 2, English only).
Windows 7 Update Drivers
Figure 2
- Select Let me pick from a list of device drivers on my computer (Figure 3, English only).
Windows 7 Browse for Drivers
Figure 3
- Select Security Devices and click Next (Figure 4, English only).
Windows 7 Security Devices
Figure 4
- Select Trusted Platform Module 1.2 (or Trusted Platform Module 2.0) and click Next (Figure 5, English only).
Windows 7 Trusted Platform Module 1.2
Figure 5
- Click Yes if you see a warning prompting you to confirm, then you should see a success message (Figure 6, English only).
Windows 7 Updated Driver
Figure 6
- You should now be able to turn on BitLocker.
If you have further questions about this solution, please contact Dell Technical Support.