ACPI\MSFT0101 is a hardware ID used by Microsoft Surface devices (and some Microsoft-branded tablet/hybrid components) to identify a HID-compliant device, commonly a sensor or touch/pen-related controller. On Windows 7, the OS does not include a built-in driver that fully supports this device ID for these newer Surface-specific components, so devices show as unknown or as "ACPI\MSFT0101" in Device Manager until an appropriate driver is installed.

While Windows 7 will run fine with this driver missing, you may experience:

Since the TPM hardware is identical, you can extract the driver from a Windows 8.1 or Windows 10 installation and manually point Windows 7 to it.

This method is 100% free and does not require third-party tools.

The hardware ID ACPI\MSFT0101 refers to the Intel Platform Trust Technology (PTT) , which provides Trusted Platform Module (TPM) 2.0

functionality. This device is natively supported in Windows 8 and 10, but often appears as an "Unknown Device" in Windows 7 because that OS was designed for the older TPM 1.2 standard. How to Resolve the ACPI\MSFT0101 Error in Windows 7

There are two primary ways to handle this missing driver depending on whether you actually need TPM security features. Option 1: Install the Microsoft Hotfix (For 64-bit Systems) If you are using Windows 7 64-bit

in UEFI mode, Microsoft released a specific hotfix to add native support for TPM 2.0. Download the Hotfix : Locate and download Microsoft Update KB2920188 Verify UEFI Mode : This hotfix only works if your system is running in , not Legacy BIOS.

: Run the executable and restart your computer. The "Unknown Device" should now be identified as a "Trusted Platform Module 2.0" in Device Manager.

Note: This driver is not supported on Windows 7 32-bit (x86) versions

Option 2: Disable the Device in BIOS (Recommended for Most Users)

For the majority of Windows 7 users, TPM 2.0 provides no benefit. It is primarily used for encryption, which is only available in the Enterprise

editions of Windows 7. If you have Home or Professional versions, you can safely hide the error. Enter BIOS : Restart your PC and press the BIOS key (usually Locate Security Settings : Look for options labeled Intel Platform Trust Technology Security Chip Set to Disabled : Change the status to Save and Exit

to save changes. The "Unknown Device" will no longer appear in Windows. Summary Table: Should You Install It? OS Version Need the Driver? Recommended Action Windows 7 64-bit (Ultimate/Enterprise) Yes (for BitLocker) Windows 7 64-bit (Home/Pro) Disable in BIOS or ignore Windows 7 32-bit (All versions) No (Not supported) Disable in BIOS to clear error

: Avoid "free driver updater" websites that claim to have a custom ACPI\MSFT0101

driver. These are often bundled with adware; the only legitimate way to "fix" this is through the official Microsoft update or BIOS settings. your system is currently using?

After reboot, open Device Manager. The ACPI MSFT0101 should now appear under Security Devices or System Devices with no error.

Note for non-Lenovo users: This driver is universal in most cases. It has been tested to work on HP, Dell, ASUS, and Acer machines running Windows 7.

The hardware ID ACPI\MSFT0101 does not correspond to a specific brand like Realtek, Intel, or Broadcom. Instead, it is the hardware ID for a Trusted Platform Module (TPM 2.0).

Because Windows 7 doesn't know how to talk to a TPM 2.0 module, it sees the device, can't find a driver for it, and flags it as an "Unknown Device" with that specific ACPI code.

Once you have installed the ACPI MSFT0101 driver successfully, verify that the TPM is working correctly:

If the console reports that no TPM is found, the driver did not install correctly. Repeat Method 2 with special attention to the manual "Have Disk" steps.