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Windows 7: Hard drive letters switching

15 Jul 2009   #1

Windows 7
Hard drive letters switching

Since installing Windows 7 (build 7100) I have been having a strange issue. I have a system drive (C:, 80GB) and 2 identical 300 GB drives (D: and E: ) used to store media. All my drives are internal SATA drives.

Oddly, whenever I restart my computer the drive letters for D: and E: switch. So Media1, which was D:, becomes E:, and vice versa for Media2.

Obviously this is a problem. Has anyone else experienced it? Ideas? I've had this same setup in Windows Vista for over a year, no problems. No hardware was changed with the OS upgrade.

My System SpecsSystem Spec
15 Jul 2009   #2

Windows 7 Pro 64 bit
Drive Letters switching

This is a windows feature whereby Windows 7 has a new boot loader that actually changes the C: drive (internally within the OS) so that the the OS being loaded is always on Drive C:.

Click on the start button and search for CMD. Run CMD as an administrator and enter BCDEDIT at the DOS prompt. This will display the boot options. They can be changed using the BCDEDIT program but is tricky - look at the examples (BCDEDIT /?). Good luck
My System SpecsSystem Spec
15 Jul 2009   #3

Windows 7

My Windows install (only OS on system) is on C: and I formatted that drive before install. I'm not having a problem with C:, rather the drives D: and E: are switching.

So to clarify, D: is Media1 and E: is Media2
However when I restart, D: is Media2 and E: is Media1

Does anyone know the cause, and even better, the solution?
My System SpecsSystem Spec

15 Jul 2009   #4

Windows 7 Professional x64

If it is changing on reboot, it makes me wonder if it's because of the SATA port the drive is connected to on the motherboard. Just a thought. You may try switching them and see if they stay the way you want them.
My System SpecsSystem Spec
15 Jul 2009   #5


I agree with Nate42nd. Make sure the 80GB is on SATA port 0.
My System SpecsSystem Spec

 Hard drive letters switching

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