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Windows 7: A disk read error occured on external USB HDD

09 Feb 2013   #1

Windows 7 Ultimate 32bit
A disk read error occured on external USB HDD

I install Windows XP to external USB HDD and Windows 7 to other USB HDD.
I have been using boot from ext. USB HDD for years because internal HDD is too small at that time and I keep it that way until recently I got problem.

I change from Dell620 to HP8560 and immediately it cannot boot from WinXP on USB. The only message is "A disk read error occured. Press Ctrl-Alt-Del to restart". I try to install again without any error during the installation process, but same error once it boot from ext USB HDD.
I still can boot Win7 on other ext. USB HDD. I upgrade it to Win8 Release Preview and work smoothly. When Win8 RP expired, I keep using it without upgrade because I usually use it for less than 2 hours.
Suddenly it cannot boot again like WinXP on other USB HDD. "A disk read error occured." I cannot find anything wrong with USB HDD.
I can still access all files on USB HDD from any system. I just cannot boot from it.

How can I know if this is hardware defect or recently Windows apply patch/update that make it cannot boot from USB anymore ?

My System SpecsSystem Spec
10 Feb 2013   #2
Microsoft MVP


Windows is not meant to boot from a USB HDD. Install the HD internally or via SATA converter cable, then run Paragon Virtualization Manager to adjust it to the new hardware.
My System SpecsSystem Spec
11 Feb 2013   #3

Windows 7 Ultimate 32bit

It was working well. I mean I can boot from USB HDD for more than a year without any problem.
Suddenly I cannot boot anymore from that USB HDD. If I boot to internal HDD, can still access all files in that USB HDD.
I try to install again the OS like what I did before but no success.
May be the boot sector is bad? But I still can read and write (restore) boot sector without error.
My System SpecsSystem Spec

11 Feb 2013   #4

Windows 7 Ultimate 32bit

I boot from flash disk with Grub. I try to boot by loading bootmgr but Grub report file not found.
Is it necessary to put bootmgr on certain sector or the first few cylinders?
My System SpecsSystem Spec
02 Mar 2013   #5

Windows 7 Ultimate 32bit

I found the root cause. I defrag, and put boot loader and boot folder at the beginning of the disk. Now I can boot from USB external hard disk again.
I wonder if the Windows folder must put in the first 128Gb area too.
My System SpecsSystem Spec

 A disk read error occured on external USB HDD

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