Оказывается, перезагрузка компьютера или его зависание вместо указанного вами выключения - распространенная проблема операционок от Майкрософт. Патч для исправления проблемы в Windows 98 здесь. Для прочих версий Windows патчи можно найти на сайте отца - прародителя. Вот что там написано:

SYMPTOMS

You may experience any of the following symptoms when you select an option in the Shut Down Windows dialog box.

If you click Shut down and then click OK, the computer may stop responding (hang) while displaying the following message: Windows is shutting down.

If you click Restart in MS-DOS mode and then click OK, the computer may hang while displaying a blank screen.

If you click Shut down or Restart in MS-DOS mode and then click OK with fast shutdown enabled, the computer may restart instead of shutting down.

CAUSE

This problem can occur because:

The computer could hang at the shutdown screen intermittently, because the Apmbatt.sys component is not responding to the system shutdown notification from the operating system and could enter an endless loop.

-or-

The computer could hang with a black screen because of the method in which IRQ holders for the video adapter are configured at boot time and disabled during shutdown by the Pci.vxd component.

-or-

The fast shutdown option modified by Msconfig.exe contains a code path in which the computer could reboot instead of properly shutting down or quitting to MS-DOS.

NOTE: The Shutdown Supplement was updated 11/99 to address a newly discovered issue that allowed continued shutdown failures on some Windows installations. Due to the added functionality in the update, it may appear on Windows Update as not installed, even if the original version of the Supplement was previously installed.

RESOLUTION

The Windows 98 Second Edition Shutdown Supplement addresses shutdown issues on computers with specific hardware and software configurations running Windows 98 Second Edition.

The English-language version of this software update should have the following file attributes or later:

Date Time Version Size File name

08/11/99 10:32a 4.10.2223 59,392 Msconfig.exe
08/11/99 10:41a 4.10.2223 65,919 Pci.vxd
08/11/99 10:46a 4.10.2223 4,384 Apmbatt.sys
04/23/99 10:22p 4.10.2222 125,057 Configmg.vxd
07/22/99 11:12a 240,797 Tshoot98.chm

The 11/99 update added the following:

Date Time Version Size File name

09/28/99 6:35p 4.10.2223 37,547 Vpowerd.vxd

STATUS

Microsoft has confirmed this to be a problem in Windows 98 Second Edition.

MORE INFORMATION

The Windows 98 Second Edition Shutdown Supplement also contains an updated Troubleshooter for Startup and Shutdown issues. The Fast Shutdown option is no longer available in the System Configuration Utility (Msconfig.exe). This update checks to see if the appropriate version of the Configmg.vxd file is installed on the computer and replaces any earlier versions with the Windows 98 Second Edition version.

Island, 1999