assigning partition letters in dual boot
in [64 Bits Windows]
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From: Tom Orle on 1 Jan 2010 12:59 "R. C. White" <rc(a)grandecom.net> wrote: >"Drive" letters are like shifting sands. Especially when dual-booting. >Please don't rely on them. Windows pays very little attention to them. > >When dual-booting, OS #1 cannot read OS #2's Registry, so it has no idea >what letters OS #2 might have assigned. ... I'm aware of the latter. That's why I installed a piece of software, like Open Office, twice - once in XP and once in W7 just to make the respective registry aware of the softwares location. despite having only one copy of Oo on drive D. So when drive D got shifted to E I ran into problems. My choice was to either edit the W7 registry and change all drive references to Oo from D to E or change the drive letters . But I lucked out - since both drives were identical copies of each other and I'm a proud owner of Acronis' backup software and was smart enough to make a backup copy after the first sucessful install, I copied/restored just the MBR onto the drive with the shifted letters and everything fell in place. This makes me assume that, when booting into W7 on a dual boot system, it's the boot manager that does the assignments of drive letters. If I look at bcdedit, it shown W7 on drive F and /ntldr on C, but after boot W7 is C and the C boot drive containing XP became G! But thanks to all for your educational insights - I learned a lot. Happy New Year!! -=tom=-
From: Sardine on 20 Jan 2010 00:02
Tom Orle wrote: > Happy New year all, > > I'm having an interesting challenge to keep me busy over this long > weekend. The basic question is: what, on a dual boot W7 system, > determines how partition letters get reassigned? > > I installed W7 Pro x64 on an existing Win XP Pro 32 bit system as dual > boot. But first I cloned my existing drive just as a precaution. > > The initial partitions on both 500 GB drives were C (XP boot), D, E > and a newly created F for W7. > Install #1: I installed W7 into the F partition and when done I booted > into W7. As expected it made the F partition the C partition, D and E > remained D and E and the XP partition became G since somehow the DVD > drive slipped in as F. > > Install # 2: Two weeks later I wanted to install W7 onto the cloned > drive. I didn't do anything different than I did during Install # 1, > but this time when W7 booted up F became C as expected, but the old XP > partition slipped into the D slot and the old D and E were shifted to > E and F!! The DVD drive became G. > > My question now is: why did these 2 identical installs come up with > different partition letter assignments? > And how can I force the assignments to look like my first attempt > since I like keeping my data partitions, D & E the same under XP and > W7? Not that it matters to the system as it works either way, but it's > less confusing to me since I would always know that certain data is on > the same partition no matter which OS I'm logged on to. > > It seems that he letter swaps must happen in the boot manager. However > I checked into BCDEDIT and the boot tab in msconfig, but found no way > to affect the letter allocations. > > Any ideas and suggestions would be very welcome. > Thanks ... > > -=tom=- > > ... |