first avoid laying blame before true  failures and cause is known, NO OPTIPEX PC told no case size either.

you then blame dell for asking you to do the simple self tests. 

you have 3 choice in this PC endless world.

1: take it to a shop where live humans work and can fix it , not guessing in a text box 12,000 miles away

2: send it to dell and they fix it. (slam dunk)

3: learn your self, (as they told you  do  , you not doing the 1 above 2 first) all you can do is test. and you don't like that.  Ive no reason why /?

now I will tell you why the mouse is dead (wild guessing, why, me fully blind as to PC not stated nor what mouse you have)

1: the mouse is bad on all USB ports,  test mouse on other PC if dead RIP one mouse buy a new one for $10

2; mouse is wireless, and the mouse batteries are dead, ,new batteries is the cure.

A: unplug the mouse with PC connected to the internet , and test it in all USB ports 1  by 1 to see if PnP

drivers can fix the mouse, drivers if they are bad.

and last NO OS stated, is this windows, if yes which of the 14 versions is it.? IDK, not me,  blinded in text box

and PC are not simple toasters,  so fixing PCs in text box is super hard. even worse on the phone.

or google why a mouse is dead, some times even lint in the optics blinds it. (some brands do)

Have you tried a new mouse? Mice do fail and are cheap to replace. Buy a $10 one to test. I'm not sure that mice are even covered under your extended warranty since it is a peripheral device like a keyboard.

Hi Savvy2,

I have understood your love towards Dell and please keep in a mind i have performed all the T/S for the mouse however they ask me to perform the HDD test and memory test, do you ever performed whatever  task is affecting your time unnecessary?

Finally for your info my system is having 3 years onsite support with Pro warranty and warranty end date is 2022, and this post is too inform other users about Dell worst support, not for the suggestion. 

Hi Mary,

Thank you for the notes.

Yes i have tested with working mice and its working fine, faulty mouse is not working in the GK systems as well.

Buy a $10 one to test. I'm not sure that mice are even covered under your extended warranty since it is a peripheral device like a keyboard. -- Its a corporate account and all the parts are covered in pro support warranty.