I previously had problems with the cdrom and floppies as described in
question "How to get both floppies a: & b: to work" now cancelled.
I finally got a: & b: both to work. Part of the problem was faulty
installation, but even after having been installed right b: refused to
work. Finally it turned out that floppy b: worked fine an in old AT
with DOS 3.2 (!) as operating system. Conversely, some floppies not
working in DOS 3.2 did yes work in windows 98. Apparently each
operating system has his own way of managing boot record, FATs, root
directory and system area, and this method of organization is not
recognized by later version. This is very annoying if you have old
floppies, but apparently nothing can be done about it.

My current more important problem is that my CD-ROM with norton internet
security again does not work. Could an adequately sophysticated virus
have disabled it?! I managed to get it work again but cannot remember
the steps I took. Now it stopped wotking again and, as before, the
computer during startup says "F1  Sec Slave Atapi incompatible. On my
system the 2 hard disks should be master 1 and slave 1 and the cdrom
shoud be slave or master 2 (do not recall which)

Would highly appreciate if anybody could me help on this.

Floppies run under a different FAT system to the hard disks. Not the
problem. As I said previously, need more info. Floppy type, capacity,
description of cables and mother board.

If the CD is the only item connected to your second IDE, the jumper
must be set to ?Master?. If it is, how old is it? For many years, CDs
have been atapi compliant but older ones require a specific driver.
This can usually be downloaded.

Best

Tanks, guzzi-ga, for your comment. If I understood right the cdrom
will work sometimes yes, sometines no, as long as the jumpers are in
slave configuration. In order to make it work reliably I will have to
open the computer, remove the floppies to get access to the cdrom and
change its jumper from slave to master, reassemble, and change setup.
If it can be done it would be simpler to install a 3-d hard disk with
jumpers to master and keep cdrom as slave. Is this possible?
As for the floppies they say "if it aint broken don't fix it" I have
very little hope that the old floppies working in DOS 3.2  can be made
to work in win98 and they are probably anyway higly outdated and
obsolete.
Please let me know if I am right.Thanks

As I understand it you have two hard disk on one the first IDE cable.
Most likely you have two IDE plugs on your motherboard, but again I?d
need to know the model to be sure. They will be marked 0 and 1, or 1
and 2, possibly preceded by IDE. For your purposes, the hard disks
must be connected to the lower numbered connector. Jumper designations
differ, but they must be set to master and slave -- the C drive being
the master.

On the other IDE cable, you are likely to have only the CD connected.
If this is so, it must be set to master on the jumpers at the rear. By
all means add another hard disk to the second IDE cable (assuming it
has two connectors), in which case it is usual to set the HD as master
and the CD as the slave. Bear in mind though that older machines are
often disk size limited. One can often flash the BIOS to upgrade but I
don?t recommend. It can go seriously wrong!

Floppies are so cheap now that if you are sure they are u/s
replacement is easy. Even cheaper if you scavenge from junked PCs.

Best