PLEASE help !!!

I had a DELL, which gave me all sorts of problems. Be that a sit may, it made 3 years.

I went to buy a Lenovo, 4 MB and a 1.7 - 2.1 ghz processor.
When I got non responding on word form day 1, I took it straight back and got my money back.

Then I bought the CAer Inspire 2 in 1.
4MB and 2.1 GHZ
She was quick and responsive.
I downloaded office - no problems.
Yesterday I downloaded Box and ESET virus.
Suddenly - disaster!!!, in fact I cant even access anything - Lucky I kept the DELL donkey around so I could send out this plea.
I could not even open word.

WTF!!! Any advice,

Oh - Windows 8 running