Not working letter (A)

Welcome Tapas Mandal,

Thank you for reaching out to Microsoft Q&A forum.  I understand how frustrating it can be when your letter A is not working properly on your keyboard.  

You can try some step below to troubleshoot the issue:  

Option 1: Update drivers 

• Open Device Manager > find Keyboards > Right-click on your keyboard device listed (e.g: HID Keyboard Device or Standard PS/2 Keyboard) and select Update driver  
• Choose Search automatically for updated driver software > Search for updated drivers on Windows Update to check for update 
• Restart your PC to see if the issue is resolved 

Option 2: Test another keyboard 

Try different keyboard to see if the problem still persists. This will help determine the issue belong to hardware or something else.  

Option 3: Try to toggle on and toggle off the Toggle Keys 

Just clicked the windows button and searched for the toggle keys setting and just turned it on and then off again. 

Or you can try: hold down the NUM Lock key for 5 seconds. Holding it for 5 seconds activates and deactivates the "toggle keys" function to see if the issue is resolved 

Option 4: Registry editing 

• Open Registry Editor  
• Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\i8042prt 
• Locate the "Start" DWORD value 
• Double-click it and set the value data to 1 
• Click OK and restart your computer 

The initial response might not address the problem. So, if your problem persists or you need any assistance, feel free to ask me by clicking "Add Comment" or "Add Answer" if you cannot add comment so your response will be visible. Thanks for your effort. 

PS: If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".     

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