Unknown software?
http://www.petri.co....-in-windows.htm
They recommend the same software -- its been well known software for YEARS AND YEARS! Back from the XP days. Been around for 2005 I do believe.
That being said I have never had an issue with setting a drive letter for a portal media storage devices, be it usb flash/thumb or full external drive, SD card, Camera, Phone - there are lots of usb devices that you plug in and allow you access to their storage.
Once you set a device to say the F: drive -- that machine should always assign it the F drive. Now if you change perm drive/partition or even a network share to use F - then yeah its quite possible to have a problem with that drive the next time you plug it in. So make it G this time, and now it should be always be G. Now if you plug it into a different machine it might be D or E or Z, etc. If you want it to be G on all your computers - then set that once and you should be done.
Or you could use software like above to make sure you disks always show up with a drive letter vs windows getting confused be cause there is an overlap in the assigned letters, etc.
If you having issues with drive letters - just mount your devices to a folder, you don't have to assign a drive letter to access it it could be c:\usb or d:\thumb that the device is mounted too.
You can also just remove the old registry entry that points to your drive letter that conflicts for that device, or change it in the registry so that device gets assigned a different letter - this article goes over how to do that
http://www.mydigital...e-drive-letter/
I pointed to the software because thought it would be a easier solution that having you dig in the registry. But you can that route as well without having to run any 3rd party software you don't trust.
Reinstalling windows to change what drive letter it should map to some external devices is nuts! Its only a simple registry key, delete the one for your device that assigned it a drive letter you have now used for a different partition - and it should then pick a free one.
Oh **** that icon on my desktop is in the wrong place - better reinstall the OS