You are correct in that, at times, on some models (and, at times, on all
models in the case of Compaq) they used a non-standard boot scheme with
non-standard boot records.

Compaq wanted to get around the fact that the "MBR" only allows 4
partitions on a drive, period (which has been the case from the original
IBM PC-XT in 1982 to this day).

I'm not sure what IBM was doing, but I know that if you took a drive out
of some IBM Thinkpads and put it into another machine, or if you took a
drive formatted in a non-Thinkpad and put it into some Thinkpads, the
drive geometry was not seen the same, and file and drive corruption
would occur as a consequence.

John Doue wrote:
> Barry Watzman wrote:
>> I think that is incorrect; I think that a clean install does NOT
>> necessarily create a new MBR.
>>
>> You have some options when you do an install; you can use an existing
>> partition (with either a "full" format or a "quick" format) or you can
>> delete and/or create new partitions. But NONE of those actions
>> replaces the MBR, which is a portion of the drive itself and not of
>> any one particular partition (each partition has it's own boot record,
>> but those are separate from the MASTER boot record). I don't know
>> that ANY of the options when doing an install from an XP CD rewrites
>> the master boot record, although several of them will rewrite the
>> partition boot record.
>>
>> The only two ways that I know of to be sure that you get a new MBR are:
>>
>> 1. Run the old MS-DOS FDISK program using the /MBR option .... this
>> explicitly rewrites the MBR
>>
>> 2. Run a program the blows away the MBR, which will leave the drive
>> without an MBR, forcing it to be recreated to install any OS. The
>> program that I use to do this is "ZAP", which was an IBM program that
>> was, at one time, originally on the IBM (later Hitachi) web site, but
>> it seems to have been removed. It writes binary 00's to the first
>> several cylinders of the drive.
>>
>>
>> BillW50 wrote:
>>
>>>
>>> Yes a clean install does recreate a new MBR. But something could be
>>> modifying it. As it seems to stick for awhile and then poof, right?
>>>
>>>> I reset the BIOS to its defaults at one point to make sure that wasn't
>>>> the problem, but it made no difference.
>>>
>>> Most BIOS uses flash memory. And sometimes flash fails. Thus either
>>> the settings won't stick very long or not at all. A weak RTC battery
>>> can also cause similar symptoms, but it is rare it does.
>>>
>>> I just worked on an EeePC 702 that couldn't read the SSD (solid state
>>> drive). And I couldn't flash the BIOS either. Pulled the SSD out and
>>> popped a new one and everything worked again. I could even flash the
>>> BIOS. Weird that the BIOS needs a working drive just to flash the
>>> BIOS. Who would have guessed that one?
>>>
>>>> Considering that two drives (one old, one brand new) both behaved the
>>>> same way, I too tend to suspect the IDE controller.
>>>
>>> Yup, you are probably right. Although I wouldn't write it off yet. ;-)
>>>
> Barry,
>
> I tend to agree with you. And if memory serves, Compaq is (was) one of
> those manufacturers which made a point of doing things differently with
> regards to hard disks MBR, same as IBM with Thinkpads.
>
> The symptoms the OP described appear to me as typical of HD failure and
> I am not convinced what was attempted is enough to decide the IDE
> controller is shot.
>
> As you suggest, I would run first chkdsk /mbr on a new HD in that
> machine before attempting a new install of Windows.
>