desperate help with program files x86 reinstall basic

HELP DESPERATLEY NEEDED PLEASE

Hi I need expert advice please, i have a laptop acer es1-612-csyw , and i desperatleyy need to reset /refresh it as have a virus . ive seen how to do this on vids and its simple enough. the problem i hav is i have no idea how to put the programs back on, to actually initiate the reinstallation of them (im a novice but with step by step guaranteed instructions,i can do it)

the programms list i will put at bottom. so it said it will make a copy of the programs files that i will lose (for refresh ,but i did not go ahead with it) . so what do i do? save all the program files ,and put on external usb hard drive? and then refresh and plug it back in, but how to i initiate the reinstallation of all the essential programs ? they dont seem to have any kind of basic set up just click icon etc . they are essential ones such is intel , internet explorer ,microsoft office etc.

and i assume windows will stay same so not need to reinstall windows at all it says i wont am just totally lost , i dont want to refresh and then be stuck with a unusable computer .

so it created a windows Program Files (x86) and within there is ..well loads ,of the programms it will remove . so how do i activate these programs once ive refreshed ? real ultra simple instructions please i dont know how to activate/reinstall these programs and will be stuck without them.i have windows 8.1 . i have NO disk or anything for any programms,the laptop was new but didnt come with any disk and was very easy to set up

i wont bore you with it all but im very ill and need my computer as can barely talk or move its my lifeline really . the virus means the pay as you go mobile broadband dongle i use..the data is being swallowed MASSIVELY so please help,im desperate to fix asap many thanks really appreciate help but please only expert advice (but in beginners terms ha )

many thanks for your help really appreciate it

Have you tried to remove the virus ?

If Windows Defender won't remove it, there are many free anti-virus programs available.

I use Avast.
The paid version.
I haven't had a virus for many years.

There is https://www.malwarebytes.org/antimalware/

Others here may offer more advice.
It may be easier to remove the virus than to refresh or reinstall.