Let's start with troubleshooting the most common problems for usb drives that disappear in Windows XP:
Determining if your USB ports are USB 2.0 (Windows)
USB 2.0 ports will show as "Enhanced
" in device manager.
To open device manager:
Microsoft Windows 2000 and XP users enter the Windows Device Manager by clicking:
1: Select Start > Settings > Control Panel.
2: Double-click the System icon.
3: Click the Hardware tab.
4: Click the Device Manager Button.
Once in Device Manager click the plus sign next to "Universal Serial Bus Controllers". This will show the USB ports and many of the USB devices on your PC.
Look for your PIC to USB host controller. If it says Enhanced then your USB port is 2.0. If it doesn't say enhanced then your USB port is 1.1.
Note that some systems have both USB 2.0 and 1.1 so you will have to figure out which is which by reviewing the manuals that came with your PC and add-on cards.
If your USB ports don't show up under "Universal Serial Bus Controllers" and you are running Windows 2000 or Windows XP then you may need to load additional drivers or apply a service pack (collection of software patches) to your operating system. Note that Windows XP did not support USB 2.0 until service pack 1 and Windows 2000 added support for USB 2.0 with service pack 3 (and provided better support with service pack 4).
A few tips for best performance from USB
If you are using USB 1.1 consider purchasing an add-on card with USB 2.0 ports.
If you have several high speed devices put them on separate USB root hubs (root hubs are the ports on the back of the computer). Some examples of high speed devices would be external hard drives, USB Ethernet adapters, USB sound cards, USB video capture devices.
Defrag the drive. If you move and delete a lot of files your files can become fragmented. Running the defrag utility in Windows can often improve the performance of a slow drive.
Many existing systems require a BIOS update to properly run Windows XP The Bios must be updated before Windows XP is installed.
A clean install of a new Windows operating is always the preferred method of upgrading. To completely avoid some of the user reported USB problems associated with updating Win9X systems to WinXP, I recommend a clean install.
When clean installing or upgrading your operating system, always unplug all USB devices except for USB keyboard and/or mouse. Follow this [url=www.usbman.com/Guides/Clean%20Install%20of%20Windows.htm] Clean Install Guide[/url] to ease the pain of a clean installation and safely backup your valued personal data and settings.
AMD 756 Based Motherboards
WinXP Professional does not recognize or properly enable USB on motherboards based on the AMD 756 Chipset. Installation of the latest [url=www.amd.com/us-en/Processors/TechnicalResources/0,,30_182_871_2336~4512,00.html] Bus Master Drivers[/url] from AMD have helped some users. Unfortunately, most users needed to install a [url=www.usbman.com/Guides/Upgrade%20Card%20Manufacturers.htm]PCI/USB[/url] card as a work around.
SiS USB Registry Patch (Windows XP)
This patch fixes the undetectable problem with SiS USB controller on Windows XP:
SiS USB Registry Patch - [url=www.usbman.com/WebDrivers/sis-usbdetect.exe]Usbdetect.exe[/url] - 54KB - 12/17/2001
Note: After you apply the patch, you may need to refresh the USB driver stack.
Remove all USB devices (except USB keyboard and/or mouse) from the Device Manager in the following order:
2: HID and/or Composite USB
3: USB Root Hub (s)
4: USB Host Controller (s)
5: Shutdown and reboot
USB Device Stops Working or Won't Resume
WinXP by Default turns off USB Root Hubs to Conserve Power causing some devices not to resume correctly after Windows resumes from sleep, hibernation or computer inactivity
In the Device Manager > Universal Serial Bus Controllers > USB Root Hub > Power Management, Uncheck the box per the illustration below. Uncheck all boxes on all root hubs.
Allow the computer to turn off this device to conserve power.
Slow Boot Up:
The more USB devices installed the slower the boot up. Windows XP slow boot up issues have been experienced in many test labs and reported by other users. Although, all systems are susceptible, VIA based motherboards appear to be more vulnerable.
Installing Windows XP to a drive that is formatted FAT 32 has proven to be the best way to reduce boot up time.
The following information from [url=www.microsoft.com/hwdev/platform/performance/fastboot/fastboot-winxp.asp]Microsoft[/url] describes issues and solutions for achieving fast system start up and a tool to trace your boot up process.
The design goals for Windows XP on a typical consumer PC are:
* Boot to a useable state in a total of 30 seconds
* Resume from Hibernate (S4) in a total of 20 seconds
* Resume from Standby (S3) in a total of 5 seconds
[url=www.microsoft.com/hwdev/platform/performance/fastboot/fastboot-winxp.asp]Fast System Startup for PCs Running Windows XP[/url]
Describes issues and solutions for achieving fast system start up on PC systems running Windows XP.
[url=download.microsoft.com/download/whistler/BTV/1.0/WXP/EN-US/BootVis-Tool.exe]BootVis.exe Tool[/url] - Microsoft performance trace visualization tool for use with Windows XP systems.
Note: This version of BootVis.exe is compatible with the final release of Windows XP (build 2600) and resolves a compatibility issue when using third-party IDE drivers.
Like all new operating systems Windows XP has it's own unique set of quirks and problems. I have received quite a few USB / Windows XP problem reports. As issues are resolved with this new Operating System, you may see new tips and guides posted in the Windows XP forum.
[url=www.usbman.com/WinME%20USB%20Guide.htm]Windows XP USB Guide[/url]
If your using the hard drive connected thru a USB hub and your usb controller has a SIS chipset, [url=support.microsoft.com/default.aspx?scid=kb;en-us;892050]read this[/url] Microsoft article.
Also, [url=support.microsoft.com/?kbid=822603] this Microsoft article[/url] might help.
827&iterationID=1&sessionID=anonymous|3466199]General USB Troubleshooting in Windows 2000 and Windows XP (Q242062)[/url]
827&iterationID=1&sessionID=anonymous|3466199]USB 2.0 Controller Is Displayed in Device Manager with an Exclamation Mark (Q292734)[/url]
[url=www.usbman.com/WinME%20USB%20Guide.htm#SiS]USB devices sometimes undetectable issue on Windows® XP with SiS USB controllers[/url]