Firstly, don't type with caps lock on its hard to read and is known as shouting.
You can reject the PC under the Sale Of Goods Act because it sounds like it is not fit for the purpose it was sold for.
To do this you need to write to Dell and send the letter by special delivery (you can then prove they got it) stating that you want the PC collected within X days (7 or 14 is good) and that you want to be refunded in full. If you do not hear from them by X date you will not contact them again but take legal advice.
Something to try, when you first turn your PC on Press F12 on the keyboard. You will then be given a series of options, one is to boot to a diagnostic mode. Do that and run all the tests (be warned it may take a while) and see if it passes or fails.