Wolfman World View: DIRTY POOL

My New Dell Computer on the Left
My Old Dell Computer on the Right
I can use the old computer standing up

Dell Inspiron iM5030-3413B3D 15.6-Inch Laptop - 3D Black

Dell is a world wide company.
I had conversations with at least 2 people in India in the last 2 weeks. I also talked to 1 or more people in Canada.
I bought a new Dell desktop computer. I learned that software discs are no longer provided with the computer automatically. However, I did get them without any hassle.
Dell has a new setup where software can be downloaded from one of their web sites. The web site is loaded on the computer, and lasts for one year. It can be renewed each year for about $20. They try to persuade customers to upgrade to a more expensive web site for approximately $40. So, if you pay for the web sites for ten years, you pay $200 to $400 to be able to download software installed on your computer. The web sites also backup selected files on your computer.
Dell Microsoft McAfee
All three of these companies operate world wide.
McAfee Security was preinstalled on my new computer. It was free for about a week, and then you were urged to pay McAfee money to keep it.
So, one day before it was to expire, I tried to remove it from my hard drive. To make a long story short, I was unable to do so. An error message came up which said that the program could not be removed until McAfee had finished uninstalling. I left the computer set to give it time to uninstall. The message persisted even after 24 hours. I tried shutting the computer down. The computer crashed. A Blue Screen of Death came up repeatedly.
I sent an email to McAfee, because I was unable to talk to a real live person. It is too early to tell the results of that.
I called Dell. They wanted me to pay for support to remove McAfee. I refused. I would have formatted the hard drive before I would have paid for support.
My son is extremely talented with computers. He succeeded in removing McAfee at first. But when he left the computer, it crashed, and the Blue Screen of Death reappeared.
He worked some more, redeleted McAfee, and the computer started operating.
Security Software
So, now I need to install security software; right? Wrong.
My son told me about Windows Defender which is a default program in Windows 7. It is a part of, and is turned on by, Windows 7. No other security software is necessary. I checked my computer, and Windows control panel told me that Windows Defender was in fact turned on.
So tell me please, why did Dell install McAfee Security software on my computer? Why was I unaware that Windows Defender was a part of Windows 7? Did McAfee Security influence me to make a mistake? I’ll leave the questions about the behavior of the McAfee software to your thoughts.