Hello,

First, some info. about the PC:

- motherboard is Intel SE440BX-2 (4 PCI slots, 1 PCI/ISA slot, 1 ISA slot)
- CPU is Pentium III 550 MHz
- operating system is Windows XP Professional with SP 2

The PC came with one 3.5" floppy drive. This motherboard supports only one floppy drive. This was verified by reading the documentation on the motherboard from the Intel web site.

I wanted to add an old 5.25" floppy drive to the PC. So, I put an old I/O controller card (MIO-400 KF) in the empty ISA slot and the 5.25" floppy drive in an empty bay. I disabled all functions on the controller card except for the floppy function (i.e., all serial port, parallel port, game port, IDE, etc., functionality was disabled). I connected the 3.5" floppy drive on the first connector on the floppy cable and the 5.25" floppy drive on the second connector, and the tail end to the ISA controller card. In the BIOS on the motherboard I disabled the motherboard floppy controller.

When the PC is rebooted, Windows finds the new controller and the two floppy drives and configures them without any problems. "My Computer" shows both drives. Device Manager shows the floppy controller and the drives to be working properly.

Here is the problem:
Neither drive will read from or write to any floppies. If I double-click on either drive, I get the error, "Please insert disk in Drive A" (or Drive B, if that is the one I double-click on), even though there is a diskette in each drive. For both Drive A and Drive B, when I attempt to read or write to them, the drive light comes on and I can hear the drive spinning. However, ultimately I get the error message described above. If I try to read or write using the MS-DOS command prompt window, I get the error message, "Device is busy."

I have tried the following with no success so far:
- used many different floppies with no change in behavior
- replaced the floppy cable with no change in behavior
- replaced the I/O controller with another one (from SIIG) with no change in behavior

Is this a problem with Windows XP?
The driver for the floppy controller is called fdc.sys and is from Microsoft. The driver for each floppy drive is called flpydisk.sys and is also from Microsoft.

The PC has been rebooted multiple times with no success. I even uninstalled the ISA controller using Device Manager and reinstalled using "Add Hardware Wizard" with no success.

This motherboard supports only one floppy drive
One floppy drive or only one floppy on the floppy channel. If the latter then why have both your floppies on the same ribbon cable.

Perhaps I'm missing something but dont you need two floppy cables; one to the mobo channel and another to the controller card?

One floppy drive or only one floppy on the floppy channel. If the latter then why have both your floppies on the same ribbon cable.

Perhaps I'm missing something but dont you need two floppy cables; one to the mobo channel and another to the controller card?

The motherboard only supports one floppy drive. I think you could also say that it supports only one floppy on the floppy channel.

That is why I disabled the floppy controller on the motherboard and am using the add-in ISA floppy controller. This controller will control two floppies. I have always seen only one cable being used whether it is one floppy or two floppies (just like the IDE cable that supports two IDE devices). The floppy controllers have only one connector where you can plug the cable in.

I can have only one floppy controller enabled -- either the motherboard controller or the add-in controller. Otherwise, there are resource conflicts.

Looks like I was right - I was missing something.

Best guess now is that it could well be WinXP related and related to the diskettes themselves. That is that some floppies have no media descriptor byte on them. This doesnt matter with earlier versions of windows but can cause problems similar to what you describe with WinXP, which since it cant "identify" the drives correctly can't even format them.

You could try a floppy image from, say bootdisk.com, to create a floppy on another pc. It should contain a media descriptor byte in its partition table and overwrite the whole floppy sector by sector.

I guess you could also try true dos by attempting to boot to a dos or win9x boot floppy diskette.