Solution to change hard disk DMA mode to PIO

As we all know, hard disks can run fast only when the DMA mode is enabled. To enable the DMA mode for various hardware devices, except that the DMA support option must be enabled for the motherboard BIOS, the IDE device in the Windows operating system must also be set to the correct DMA mode. However, it is said that if Windows XP encounters multiple access errors (for example, it fails to shut down normally after a crash), the hard disk will be automatically downgraded to a lower speed DMA mode or a slower PIO mode. How should we find and solve this problem?
Hard Disks produced in recent years generally adopt Ultra DMA 33/66/100/133 transmission modes (DMA100 or more hard disks can be purchased on the market). The larger the number, the faster the data transmission speed. Generally, Windows XP automatically sets the hard disk to the correct DMA mode based on its technical specifications.
But according to a technical article published by Microsoft (http://support.microsoft.com /? Kbid = 817472) indicates that when the XP system encounters multiple errors, the transmission mode of the hard disk may be automatically modified or downgraded by the system. If you find that the disk speed suddenly slows down, this problem may occur. Next, I will tell you how to force the DMA mode of the Fixed hard disk to keep your computer in the optimal state without modifying the operating system.
1. First, how can we know whether the DMA mode of the hard disk has been modified by the XP system? Right-click the "my computer" icon on the desktop, and click "manage" in the shortcut menu that appears later.
2. Open the "Computer Management" window, click "Device Manager" in the small window on the left, and expand "ide ata/ATAPI controller" in the small window on the right ". On the "Main IDE channel" item, double-click the left mouse button to bring up the "Main IDE channel properties" setting window. Then switch to the "Advanced Settings" tab to check the actual DMA mode in the XP system.
The "device 0" and "device 1" columns represent the first hardware device and the second hardware device connected by the IDE cable. Please identify the location of your hard disk. For example, in my computer, "device 0" is the hard disk, and "device 1" is the optical drive. If another IDE cable on your computer is followed by another hard disk, check the content of "secondary IDE channel.
The codes in the "current transfer mode" column are: "Mode 0 (DMA)", "Mode 2 (DMA 33)", and "Mode 4 (DMA 66) "," Mode 5 (DMA 100) "," mode 6 (DMA 133) ", please judge by yourself against the technical specifications of the computer hard disk.
3. If the system DMA mode shown in the preceding step is different from the actual disk type, it may have been modified by the XP system. At this time, even if you change the current transmission mode to the correct DMA mode in the "current transmission mode" column, the system will jump back to the original settings next time you start the system. Therefore, you must switch to the driver tab, click the Uninstall button, and restart the computer.
4. After reboot, click Start> run on the XP desktop, and enter regedit to run the Registry Editor Program. Then find the following primary key: "HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Control \ Class \ {4D36E96A-E325-11CE-BFC1-08002BE10318} \ 0001"
5. Find the primary key, right-click in the blank window on the right of the Registry Editor, and click "new"> "DWORD Value ".
6. Rename the DWORD Value as "ResetErrorCountersOnSuccess" (case sensitive), right-click the DWORD value, and click "modify" in the shortcut menu that appears.
7. After the "Edit DWORD Value" dialog box appears, change "value data" from "0" to "1", and click "OK. After the computer is restarted, the system can now forcibly switch back to the DMA mode that matches the hard disk specifications.
8. If your computer contains more than two IDE controllers (with more than two hard disks ), in the "HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Control \ Class \ {4D36E96A-E325-11CE-BFC1-08002BE10318}" primary key, there may be "0002", "0003 "...... And other sub-items, representing each group of primary and secondary IDE channels. Please modify them in the same way.
Similarly, you can also refer to Microsoft's technical Article http://support.microsoft.com /? Kbid = 817472, to solve this problem, I played the machine, this kind of problem occurred a long time ago, so I don't know where to solve it. Sometimes I have to install the system once in two days, I also did not dare to install other software. I always thought it was caused by the installation of a software. At last, it was not the case. so I found this article, and now I am using this method, hoping to solve it.