That the PC didn't get an address from the unknown router or such and use the self assigned IPs.
As it stands, it doesn't show where the problem is. Tell about your router, etc.
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It seems that your issues are with torrents and proxies. I don't think that's a "network problem". Until solved, don't use those.
Anyway, I couldn't guess that "solved with cache" means that you did a reset of Windows nor that "any other program" means "except from browser". The help you can get here is as good (at most) as your description of the problem.
If resetting Windows didn't help, go back to factory settings (or to your latest image backup) and all will be as fine as it was at that time. Then gradually go ahead again. It takes some time, but it's guaranteed to work if there are no hardware issues.
Post was last edited on December 16, 2018 2:01 AM PST
If you need to download a program for school and you can't do it at a school supported location, go and complain with the IT support desk.
If you can't do it where you're now and it's not supported by the school IT, take your laptop with you to any other place where you can use Internet to download it or download it to a smartphone (I suppose you have one, most students have) using the data connection on the phone and copy it from there to your PC or laptop.