How to secure and be safe

I write to ask you for your technical support, (this is somewhat personal), in relation to my HP laptop. This is machine I being using for a long time, and it is yet strong. I am happy with it though I wish I have a budget for a new one.

I feel there has being “hackers” or certain unwanted applications or software being installed, while I am on line. Lately I have installed NordVPN (3 years) and I am using Bitdefender total security. Thought I have repeated sent them tickets they say everything is fine. But when I ask for the lab reports they decline to give. Especially Bit Defender. I believe they do not want to admit there is a hole or a bug, in their software.

One other issue is there are too many startups. I have no clue which is a good one or which one is from a “hacker”

The reason to seek your technical help is to, seek advise if there is a free software where I can run and clean my computer.

Please don’t create multiple post under different categories

Thank you! Without knowing I replied to both the links I was provided with. I was not quite sure which one to use.

I will adhere to your advise.