Description: The environment is incorrect. Stop code 0x000000a: IRQL _ not _ less _ or _ equal ◆ Error analysis: it is mainly caused by driver failure, defective software and hardware or incompatibility. From a technical point of view, this shows that there is a memory address in kernel mode that is accessed with too high IRQL. Example 1: When installing Windows 2000/XP, besides checking whether the hardware meets the compatibility list, the following measures should be taken. (1) During installation and startup, when the message "Setup is checking the hardware configuration of your computer" appears, press F5, and when prompted, specify the correct computer type and hardware abstraction layer (HAL). For general users (only one CPU is installed), please specify "standard PC HAL". (2) Turn off all cache and shadow settings, plug-and-play options and virus protection functions in CMOS settings. (3) Disconnect unnecessary hardware for computer startup, including network card, built-in modem, sound card and the second hard disk. At the same time, check whether the jumper of the hard disk is set as the main jumper, and check whether the jumper of the CD-ROM is correct. (4) If you upgrade from Windows 2000 to Windows XP, you need to uninstall all antivirus software and startup management software (such as Norton GoBack), remove all unnecessary hardware, and disconnect all USB devices and printers. Example 2: When using Windows 2000/XP, (1) appears. Check the newly installed software and hardware drivers and uninstall or disable them. Safe mode is recommended for this task. If it is a driver, it is recommended to use the driver return function of Windows XP to restore the original driver. (2) If Windows can't start, first try to use "Last Good Configuration" to solve the problem. If not, solve it according to the following methods. ★ Windows XP: Use the installation CD to enter the recovery console, run the command "%systemroot% \ system32 \ restore \ rstrui.exe", and then follow the prompts to recover the system. ★ Windows 2000: Write down the file name displayed in the blue screen information, find a computer with similar software and hardware configuration, open the registry editor and find [HKEY _ local _ machine \ system \ current control set \ services]. The registration information of each device and service in the system is saved here. Please check every message carefully, especially "DiskPlayName" in the right pane. Some drivers will indicate the purpose description of the device driver here. In addition, there is a corresponding file name after the "ImagePath" key value, which is also the main point to pay attention to. You need to compare the file names you copied. Use the Windows 2000 installation CD to enter the Recovery Console, then enter the directory C:\WINNT\System32 and enter "listsvc". After entering, the service or equipment installed in the current system will be listed, and the name of the service or equipment related to the newly installed hardware or software will be found and recorded. Then, enter "Disabled Service or Equipment Name" and press enter to stop.