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WinPE: Booting from USB CD-ROM, no drive letter RRS feed

  • Question

  • So, I have deployments ready for two products. My custom deployment method using WinPE and a custom app is complete and works great. I've tested using CF and USB media. I've also created a DVD and tested it using a eSATA DVD drive.

    Note, it all works as intended. Then I tried to use the DVD in a USB DVD drive and.... it fails. Spent a full day reviewing the deployment system. Why does it work when run through an eSATA connection, but not a USB connection.

    It appears that WinPE 3.1 does not assign a drive letter to the USB DVD drive, right away. However, for testing, I changed my app so when it throughs the error that it cannot find the drive, I get a command prompt. From the command window I again execute the app and it works fine. I can see that it is being assigned drive D:. Does opening the command prompt force the drive letter enumeration?

    Note that my app looks for a file in drives C:, D:, E:, and F:. It errors out in that it cannot find D:, E:, or F:. I expect it with E: and F: as only the USB DVD and internal SATA drive are connected, but why does it not see D: until I open a command window?

    Friday, March 15, 2013 1:30 PM

Answers

  • It sounds like timing. If it was possible wait longer does the drive letter get defined?

    -Sean


    www.annabooks.com / www.seanliming.com / Book Author - Pro Guide to WES 7, XP Embedded Advanced, Pro Guide to POS for .NET

    • Marked as answer by VanAwful Saturday, March 16, 2013 7:09 PM
    Saturday, March 16, 2013 4:22 AM
    Moderator

All replies

  • Is the USB port USB 3.0? If so you need to inject the USB 3.0 driver into the WinPE image.

    -Sean


    www.annabooks.com / www.seanliming.com / Book Author - Pro Guide to WES 7, XP Embedded Advanced, Pro Guide to POS for .NET

    Friday, March 15, 2013 3:16 PM
    Moderator
  • Hi Sean,

    No, it is not USB 3.0.

    When the system boots WinPE and runs my app place of winpeshl, the USB CD-ROM does not appear to get a drive letter. However, if I open a command window the the USB CD-ROM gets a drive letter.

    Friday, March 15, 2013 7:28 PM
  • It sounds like timing. If it was possible wait longer does the drive letter get defined?

    -Sean


    www.annabooks.com / www.seanliming.com / Book Author - Pro Guide to WES 7, XP Embedded Advanced, Pro Guide to POS for .NET

    • Marked as answer by VanAwful Saturday, March 16, 2013 7:09 PM
    Saturday, March 16, 2013 4:22 AM
    Moderator
  • Thanks Sean, that seemed to be it. I added a small delay at the start of my app to allow the system to catch up.

    Saturday, March 16, 2013 7:09 PM