Can you please tell me that my computer is OK! I keep receiving these pop-ups every day, this is what they say:

“Your Personal Information May Have Leaked. IMMEDIATE RESPONSE REQUIRED
Your Hard Disk May Have Trojan Virus! Please Do Not Try to Fix Manually, It May Crash Your Data.”
What happened to my computer? I did not install any suspicious programs recently. Why is this happening?
Is there a way to stop these alerts and clean my computer?