I am not sure in which part of the forum to post this but this seemed like the best place, hope that is okay. I am having a bit of trouble with my pc, my knowledge is very limited so I wanted to ask for some advice here. My laptop (running windows 10) behaves strangely and I got multiple pop-ups from my antivirus (ESET) without finding the actual problem (even with tech support). On top of this programs are sometimes crashing. I will give the list of problems below but let me start with that I am planning to do a windows re-install as my pc already is slow. With this procedure, I hope to get my laptop a bit faster and that will hopefully cure the possible "infection" problem also. The question for me is now if it is necessary to check whether I am infected or that the problem will go away with re-installing windows (which I assume). Besides that, I do not want to get re-infected when I copy files back to my laptop from the back-up. As said, I am not experienced so I do not know where the problems may lie. Below I will give the kind of problems I have now, maybe that helps.
It started with a pop-up of a port-scan a few months ago. After that a weird ad was blocked repeatedly (when only Hotmail was open). The ad did not concern me much but when I later got a little pop-up window saying something like "server is busy", I clicked on OK figuring it was one of my programs having problems to connect to the server. Immediately afterwards I realized I had never seen such a pop-up, making me suspicious. Besides that, programs started crashing the last few months, windows updates get installed and the laptop asks for an update immediately after not seeming to have installed the last. A few weird pop-ups about a cache poisoning and some other messages blocking websites/incoming traffic made me inclined to post a message here. It could be that this are all non-correlated events but I wanted to be sure and check here. I became a bit paranoid about something possibly wanting to break in or some weird virus.
As said I am planning to re-install windows. First, I will make a back-up. I will re-install all programs by hand I will only copy some files back (most is on Dropbox). I will keep the back-up for a few weeks in case I forget something. I am changing security software also in the process, I bought Norton for the coming year as it had better results in some tests I had seen. I will scan the back-up hard drive before copying my files back (maybe in some sort of quarantine mode?). Is this enough or should I take extra precautions like checking before re-installing or other steps in the re-installing process?
I hope you can help!