Put all your important data on one external stick/drive,
afterwards delete everything in your user folder (not only libraries/documents, delete c:/your username completely)
get an install media for windows (stick, cd, etc),
boot from that^ and install new windows while formatting all partitions and wiping the disks clean,
first thing on the fresh system install
Malwarebytes, (if you're lucky they still got that free trial premium offer - activate it), do a full scan.
Use it to scan your data backup stick/drive - before accessing it! (Turn off Window's autorun for external medias before connecting it)
If all goes as planned restore your backup and reinstall your programs.
If you still have the same problems after
that procedure, throw your PC and every peripheral with a controller chip in the trash and change all your passwords using your phone's browser.
