What are you running? (e.g., Windows 10 64-bit) What is the exact model number of your M-Tech device? What error message do you see in Device Manager, if any?
Most M-Tech Bluetooth USB adapters use reliable, third-party chipsets manufactured by companies like Realtek, Broadcom, or CSR (Cambridge Silicon Radio). Method A: Use Windows Update (Recommended) mtech bluetooth driver
Techkey 100M Class 1 for better antenna performance. What are you running