New Mini 10 with problems

I received my Mini Ten about 3 weeks ago and immediately noticed that when typing in my email (Comcast) that the cursor would jumb backward often while typing so that the word I typed ends up in the middle of a sentence I was throught typing.  Also when I turn on the computer, it was taking a very long time to power up and then get to the desk top, LONG TIME.  IF I go to word pad typing is fine with out the cursor jumping.  The tech on the phone took control of the computer and looked here and there, saw some "errors" made them say satisfactory but then would again say error when he went back to them. All of a sudden the computer made a god awful noise and he remotely could not stop the noise so asked that I shut it down quickly.  I did.

Also notice now that the size of the printing in Explorer on my Comcast sometimes look like it is getting bigger and then gets smaller again at one point before calling Dell it was so big I could not even look at the Comcast site because everything was so big.

After much discussion(2.5 hrs on the phone)   Dell replaced the hard drive very quickly.  I have the same problem with typing within the email program only so clearly it is not the hard drive.  I am awaiting the tech people to be calling me to see if the hard drive replacement cured the problems.  The computer boots up quicker for sure, but the cursor still jumps backward when using email

Any suggestions, I do not want a new  computer just this one to work

email

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