Buy a read-only U disk, install a pe, reinstall the system. Then boot into pe, full format, and then write a total of zero, and then reformatting, and then partition the system installed on it.
Most of the computers affected by the virus are still stuck in Microsoft's XP system. As early as 2014, Microsoft announced the security maintenance of the system. Up to now, there are still a large number of public departments and public institutions that are still sticking to the system.