360Cs/500MB drive/Urkle/Can't see drive from a: boot

[brendan@clark.net (Brendan Hoar)]

We swapped a new 360CE's 500MB drive into my 360Cs a while back.  Always
booted off of it.

I found URKLE on my machine the other day.  As per McAfee's instructions I
booted up w/ a PC-DOS 6.3 boot floppy.  I can't see my hard drive from the
floppy boot.

But I can boot from my hard drive.

Anyone know if this is due to one or more of the following:

a)  URKLE causes drive to be unusable unless you boot from it?
b)  The ROMs of the 360Cs will not see the drive unless you boot from it?
(remember, the drive was originally from a new 360C-E-).
c)  Some driver needs to be added to PCDOS 6.3 to see the drive?
d)  Something else?

McAfee will not get rid of URKLE if it is in memory, which means I need to
boot from another drive.  However, I cannot see the HD if I boot from
another drive.

Help?

-brendan