Попытаться получить доступ в командную строку (Безопасный режим с поддержкой командной строки) и выполнить операции с реестром:
REG ADD "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon" /v Shell /t REG_SZ /d Explorer.exe /f REG ADD "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon" /v Userinit /t REG_SZ /d userinit.exe, /f REG DELETE "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\explorer.exe" /f REG DELETE "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\taskmgr.exe" /f REG DELETE HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System /v DisableRegistryTools /f REG DELETE HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System /v DisableTaskMgr /f REG DELETE HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\System /v DisableRegistryTools /f REG DELETE HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\System /v DisableTaskMgr /f REG EXPORT "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon" C:\Winlogon.txt REG EXPORT "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options" C:\ImageFEO.txt REG EXPORT "HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot" C:\SafeBoot.txt