thực tế là các băng tần ISM là phương tiện không có giấy phép một người dùng không có để có được một giấy phép sử dụng thiết bị trong đó băng tần. Một phụ lục thứ hai để tiêu chuẩn IEEE là các chuẩn | security 529 harm that can happen has already occurred and your actions from this point onward can prevent further harm from occurring. Unless the unwanted program has taken control of your computer and is writing continuously to disk do not power off your computer. If you were not using a virus scanner and have a program available for use run it. The chances are high that if you have a virus or another type of attack program its techniques may be recognized and the scanner can locate the program. If a scanner is not available or fails to locate any abnormal software reboot your system using an original system diskette which loads a good write-protected copy of the operating system since the original system diskette is permanently write-protected. Using the newly loaded operating system attempt to examine the files you used during the operating that resulted in an infection indicator. For example did you previously execute a command stored as an .EXE file and a directory listing shows both .COM and .EXE files If so the obvious cause of the problem is now apparent. However what happens if you cannot access your hard drive owing to the modification of your boot sector FAT or directory structure Although it is probably preferable to have used a disk recover program which keeps an image of your key hard-drive sectors on another area of your drive to facilitate data recovery you can also attempt to use an operating system command such as the DOS command SYS C which will rewrite your DOS boot sector on your hard drive if that area was modified. If this still does not fix the problem and persons you consult shrug their shoulders when asked what you should do next you may be faced with having to reformat your drive and reload your software which was hopefully backed up on a regular basis. Although this represents a situation most of us will rarely have to encounter if you have to reload previously backed-up software it is important to recognize that the cause of your .