Where and when?
1. The article [Q811493] explains that you may experience slower computer performance after you install the 811493 (MS03-013) security update package on a computer that is running WinXP Service Pack 1 (SP1), or after you upgrade to SP1 on a Windows XP-based computer on which the 811493 security update was previously installed, and that the patch can be removed if installed. This problem may be more likely to occur if you use some features of some third-party programs such as antivirus programs. For example, this problem may occur if your antivirus program is configured to scan all files when you open (or you run) them. This is sometimes called "real-time" scanning.
2. "Computer Speed and Performance May Decrease (Q3104119)."
3. The article [Q812337] explains that a Hewlett-Packard (HP) Pavilion computer may run very slowly after installing the HP software update for the Universal Serial Bus (USB) multimedia keyboard, and you may also notice the CPU is running at 100%, with the Kbd.exe file taking up over 90% of the resources.
4. File transfers and printing done by means of infrared data association (IrDA) may be slow and a print job may time out and stop printing, or it may take an extremely long time to complete, [Q823979].
5. The article [Q810063] explains the situation that when using a USB keyboard and mouse connected to a USB 2.0 Controller, they are slow to respond after a hibernation event.
PART II: - DMA vs PIO
1. Change DMA transfer mode to PIO mode, also explained in #8d below, (click Start, Control Panel, double-click System (if you do not see it, switch to Classic View in the left pane), click the Hardware tab, and then click Device Manager). Alternatively, right-click the My Computer icon on the desktop and then click Properties.
a. Double-click IDE ATA/ATAPI controllers, double-click Secondary IDE Channel, and then click the Advanced Settings tab -- if you do not see it, DMA transfer mode options are not available for SCSI drives.
b. Under Device 0 (most likely your hard disk drive and should not be changed), select PIO only in the Transfer Mode box. If you have more than one CD or DVD drive, also select it again under Device 1. If Current Transfer Mode under Device 0 or under Device 1 states Not Applicable, that device is not in use. Change only the devices that do not state such. If they do, your CD or DVD drive is on the Primary IDE Channel (double-click Primary IDE Channel and on the Advanced Settings tab under Device 1, select DMA if available in the Transfer Mode box).
c. Click OK, and then restart the computer.
3. The article [Q310751] states that when attempting to configure the direct memory access and programmed input/output (DMA/PIO) settings for a device on a WinXP-based computer, the settings may not be found in the Properties dialog box and occurs because the DMA/PIO settings are configured for each controller instead of for each device. Depending on the option set for Transfer Mode, simply changing it from PIO Only to DMA if available and then back again may cure certain anomalies.
4. The article [Q304853] states that when upgrading a Sony computer from WinME to WinXP HE, the startup sound may plays irregularly when the computer starts, and can occur because direct memory access (DMA) is not the default setting for integrated device electronics (IDE) devices.
5. The article [Q327805] states that after installing WinXP SP1, ATA-133 (Ultra DMA Mode 6) devices are not enabled even though SP1 supports it. Since Ultra DMA Mode 6 devices were not supported prior to SP1, they are not installed/reinstalled in the process.
6. The article [Q310592] describes the subkeys contained in HKEY_LOCAL_MACHINE\Enum for the specific hardware components entries for Plug and Play components of the BIOS (this includes timers, controllers, and direct memory access [DMA] chips). Each BIOS subkey starts with the string *PNP and is followed by a four-digit number that represents classes by which the components are grouped.
7. Hard disk performance may be reduced since the Windows IDE/ATAPI port driver (Atapi.sy) reduces the communications speed (the transfer mode) from the highest Direct Memory Access (DMA) mode to the lower DMA modes after a cumulative total of six time-out or cyclical redundancy check (CRC) errors occur. If the driver continues to receive time-out or CRC errors, the driver eventually reduces the transfer mode to the slowest ''PIO Mode.'' Use the Advanced Settings tab in Device Manager to view the properties of the IDE channel to which the drive is connected. READ and apply any of the resolutions for this symptom as explained in the article ''IDE ATA and ATAPI disks use PIO mode after multiple time-out or CRC errors occur (Q817472).''
8. Supplemental reading:
a. ''DMA Mode for ATA/ATAPI Devices in Windows XP.''
b. ''Instructions for enabling DMA in Windows XP.''
c. ''HOW TO: Manage Devices in Windows XP (Q283658).''
d. ''Abit Hot Rod DMA 366 IDE Expansion Adapter Does Not Work After Windows XP Upgrade (Q305028).''
e. ''HOW TO: Configure Devices By Using Device Manager in Windows XP (Q307970).''
f. ''Description of Ultra DMA (Q308541).''
g. ''Explanation of Error Codes Generated by Device Manager (Q310123).''
h. ''Programming of Transfer Mode Speed Is Not Supported by Atapi.sys When You Hot or Warm Swap Drives (Q323760).''
h. The Black Max PC site concerning ''DMA XP/2000.''
9. As a last resort and your understanding of the instructions presented in ''8h'' above, in Safe Mode, start removing the device(s) in question, and then reboot the computer to see if Windows correctly identifies the device again with appropriate driver that allows the switch to take place -- perhaps a driver you have installed is the culprit.