🚀 go-pugleaf

My understanding is that if you call CreateFile with \\.\U:
you'll get a handle to the partition U: (a logical drive),
like you're doing, and youl'll be limited to sectors inside
of that partition.

If you want to access the physyical drive (that means the
whole drive - Master Boot Record, etc) you have to call
CreateFile with \\.\PHYSICALDRIVEx, as stated in Builder's
WinSDK Online help:

------------------------------------------------------------------
The lpFileName string should be \\.\x: to open a floppy drive x or
a partition x on a hard disk. For example:
String	Meaning
\\.\A:	Obtains a handle to drive A on the user's computer.
\\.\C:	Obtains a handle to drive C on the user's computer.

The lpFileName string should be of the form \\.\PHYSICALDRIVEx to
open the hard disk x. Hard disk numbers start at zero. For example:

String	Meaning
\\.\PHYSICALDRIVE2  Obtains a handle to the third physical drive
                     on the user's computer.
------------------------------------------------------------------

I believe you must find a way of discovering which physical drive
your pen drive (or similar) is. Sorry, that's AFAIK, for now.
Search also for "Direct Drive Access Under Win32"  in Builder's
WinSDK Online help.

Regards

Eudy