Are you able to download anything in Safe Mode with Networking ?
If you are then I'd like you to download and run a scan with the free version of MBAM and then follow that up with a scan by AdwCleaner.
https://www.malwarebytes.com/mwb-download/https://www.malwarebytes.com/adwcleaner/With the latter after it has completed its scan it may list some things in the lower pane it considers to be unwanted programs.
If you have specifically downloaded them and want to keep them, then uncheck their boxes then have a look at the Log to see if it has found anything.
Close the log and then hit Cleaning where it will produce a report after the reboot.
If it hasn't found anything then it will say so.
Do all of this in Safe Mode with Networking and then see how things are after the reboot.
If you aren't able to download anything in that mode then go Start - type mrt.exe and press enter and opt for a full scan.
That scan can take a while but when done, go Start - type cmd then select Run as administrator - accept the UAC and enter these commands -
netsh winsock reset catalog
netsh int ip reset resetlog.txt
shutdown /r /t 00
and see how things are after the reboot but also run those cmds after the scans with MBAM and AdwCleaner if you were able to run those scans.