I reinstalled Windows XP on a new 320G HDD (in Dell Dimension 2350, 2.4G Pentium, 768M RAM) using DELL supplied CD's. Unfortunately the boot drive is F: (left a Zip Drive plugged in and it became C:). I went on installing applications, some of which complained about No Disk in C and similar during install. Nevertheless everything seemed to install after many Continue boxes were responded to.
I had second thoughts about future use possibly being plagued with problems caused by the Boot Drive not being C:, and looked into changing it.
Was referred to Microsoft article How to restore the system/boot drive letter in Windows
http://support.microsoft.com/kb/223188#appliesto and noted the warning For the most part, this is not recommended, especially if the drive letter is the same as when Windows was installed.
Researched your knowledge base which has many articles on this (common problem, no warnings in re-install procedures it seems), and the consensus seems overwhelmingly NOT to do it, reinstall is the best way;
Two such articles are
https://www.experts-exchange.com/questions/22918008/Change-boot-drive-letter.html
https://www.experts-exchange.com/questions/21210433/Change-drive-letter-assignments-on-System-Boot-volumes.html
with the latter saying I STRONGLY RECOMMEND not changing the system drive the others are ok
https://www.experts-exchange.com/questions/22919680/Harddisk-partition-letters-got-swapped-need-to-revert-C-and-D-back-again.html really spells it out bluntly:
Unfortunately the best solution to ensure everything is correctly referenced is to reinstall the OS. After this happens to you once (or twice) you'll not make that mistake again ... but as you've discovered there's no convenient way to change the system partition's drive letter.
Probably more than you needed to hear ... but the bottom line is simple: Re-install the OS as the only partition on a drive ... and be sure XP is designating it as C: before you continue with the installation.
Having resigned myself to learning from my mistake and some more pain, I spotted hope in
https://www.experts-exchange.com/questions/21951500/DRIVE-LETTER-CHANGE.html
which suggests that doing an XP Repair Install with ONLY the one drive connected will change it back to C:, then have to reinstall the Windows XP updates, with some applications only having to be re-installed to straighten them out.
A reference to how to do the XP Repair Install is given:
http://www.michaelstevenstech.com/XPrepairinstall.htm
Given the general consensus that a re-install of XP (with ALL other drives REMOVED) is the best action to take, followed by a re-install of all applications, I have two questions:
1. Is the XP Repair Install likely to achieve that same outcome (a risk free system) with slightly less grief (i.e is loading all drivers avoided, and maybe reloading some applications avoided).
2. Is my belief that its better to deal with changing the Boot Volume to C: now, rather than risk annoyance in future by leaving it at F:.
Any procedure to follow, and pitfalls to avoid would be appreciated.
"... 2. Is my belief that its better to deal with changing the Boot Volume to C: now, rather than risk annoyance in future by leaving it at F:." ==> Absolutely, While you could potentially run for a long time with no problems, it's not only better "just-in-case" of an errant program that still looks to C:, but also for familiarity with folks using the machine ... who can be confused by a non-standard letter. "Annoyance" is the right word -- and it's simple enough to just fix it now and never have to deal with it.
"... 1. Is the XP Repair Install likely to achieve that same outcome (a risk free system) with slightly less grief (i.e is loading all drivers avoided, and maybe reloading some applications avoided)." ==> Basically Yes. The applications will still be intact; but you'll need to re-apply all Windows Updates, etc. Note that if you have applied a Service Pack that's newer than your XP CD contains, the Repair Install will not work [it will refuse to run]. e.g. if you have an XP SP2 CD and have already updated to SP3 you can't do a repair install. What I'm NOT sure about (been a LONG time since I've made the "drive letter mistake" -- so I haven't done this lately) is whether the Repair Install re-assigns the drive letter. You can easily tell by booting to that point, and seeing what letter it SHOWS on the partition where you'll be doing the install. If it's not C:, then the Repair install won't work.
Personally, I'd bite the bullet and just do a clean install. Note that the XP installation routine does show the drive letter it has assigned to the partition you'll be installing to BEFORE you actually do the installation => you just have to remember to pay attention to it; and start over if it's not a C: [Most of us have "been there, done that" and learned that lesson :-) ]. In your case it was a Zip drive; but USB card readers; other hard drives; etc. -- ANY MSC device can cause this issue. The good news is that once XP has been installed with C: assigned as the system drive, it will always be C: ... no matter what else you connect.