Windows 7: Drive letters change when swapping hard drives

I have two 1TB drives, each containing 4 partitions, used for backing up 4 computers. These drives are regularly switched between buildings as part of our backup strategy, always having one off-site. I have assigned drive letters M,N,O,P to respective partitions. When I swap the drives, the drive letters get reset and have to be manually reassigned. I have tried several suggested methods of assigning the drive letters, including USBDM, but get no results.



Computers: HP Compaq 8200 Elite - CMT - 1 x Core i5 2500 / 3.3 GHz - RAM 4 GB - SSD 1 x 160 GB - DVD±RW (±R DL) / DVD-RAM - HD Graphics 2000 - Gigabit Ethernet - Windows 7 Professional 64-bit - Intel vPro Technology
Docking Stations: ICY DOCK MB877SK
Hard Drives: SAMSUNG Spinpoint F3 HD103SJ 1TB

Right you are using 2 different drives. Manually Assigning letter to one of them Restrict those letter from being used on the other. When you switch them out the letters have to be manually assigned again. That is how it is suppose to be. Windows Remembers each Drive serial # and or some other drive parameter and sees them as different drives, which they are.

The only way around it is to let Windows assign the letters automatically but that may not work on multiple systems if each of those system have different number of HDDs, Partition on the HDD and or different number of CD/DVD drives install in the systems.

Thanks for the quick response, edwar. I will not close this thread on the basis of the explanation. The drive swap as described has worked very well on our XP systems. I feel that this one of Microsoft's mistakes in trying to over-protect the user. Perhaps someone out there has a hack for this problem. I'm watching and hoping.

It is not about over protecting. Haven't needed to do this on XP in a while as my main systems are all Win 7 or Mac OS X, although I do still have some XP PCs.

With Win 7 each drive you connect and manually assign a drive letter to Windows remembers that assignment. So if I have 3 externals I can connect and disconnect them at any time and they will always get the same drive letter.

If I let Windows set the drive letter auto then if I disconnect drive # "1", which lets say got J as the drive letter, and connect drive # "2" it would also get the letter J assigned. If I then Reconnected drive # "1" it would get the letter K as it is the next in line. Where just a minute ago it has J assigned.
Don't think you will find a workaround but Good Luck.

In my systems I do not rely on Drive letters solely for identification. These are allowed to change as they will, which happens regularly with different drive related software utilities also.

What I do is give the partitions (drives) names. This is done at the top of the General Tab in the drive's Properties window. In this way the drive letters can change but the partition is instantly recognizable to me.

For internal drives (which don't switch around so much) I often just give them all the name "Drive". These then show up as "Drive C:", "Drive D:", etc.
External drives I might give a more descriptive name. For backups I will use "BU-1", "BU-2", etc. These will then show up as "BU-1 F:" on one computer but perhaps "BU-1 J:" on another, but the drive letter it does not matter because I can recognize the drive as my "BU-1" partition regardless.

You might give that a try!

If you give each partition on both HDD's a Volume label then it will retain it's drive letter assignment from PC to PC so long as the PC being used does not use those letters...

if only 1 of those HDD's is connected at any given time you could actually use the same 4 letters and it would work when they are swapped out...

Hope this helps.

That is what the Op has been doing, as explained in his first post, and the same drive letters will not be used. That is why he started this thread.

That also has been my experience. It drove me nuts (yeah, I know, short trip) until I decided to stop worrying about it and just use the drive name to ID the drive (I also write it on the label of the drive), same as TVeblen, and let the computer do what it wanted with the drive letters.

That's fine if you aren't using some type of automated script to use these drives as Backup points and that script can't use the Drive Name, only the drive letter.