CD-ROM drive in DOS mode, Win98 won't install App from it

I built this box myself 2 years ago and the 104S Pioneer CD/DVD drive has never caused any trouble at all. About 2-3 weeks ago, I downloaded a Norton AntiVirus 2001 demo, and ran it (no viruses). Ordinarily I avoid all anti-virus apps- they are too intrusive, too buggy, too resource wasteful.

 It was not long after that when I realized that my CD drive (assigned F: since I've partitioned my single HD) was not showing up on Explorer Tree nor in MyComputer nor Device Mangr.

I was unable to get the pc to recognize F: in any way (not even by DOS). Hware Install Wizard didn't see it, etc.

         I took this as evidence of a viral injury and promptly paid for the Norton to register and run it. The Symantec method was such a mess that
 the registration never was acknowledged by the demo , I asked for a refund and recently *completely* extricated the Norton from my system.

         While dealing with the tedious correspondence to Symantec I looked for other remedies. Add New Hware didn't work.  I had the idea of getting Pioneer's 104S drivers off the Web .

         That provided a file ATAPI_CD.SYS which looked promising. I ran the little .inf and then copied the ATAPI_CD.SYS into a few promising
places like C\Windows\System & System32

         It worked! Things appear a little different now. I don't recall seeing so much ASCII text about the 104S during posting- but I do now. The F: has returned to Explorer, the contents are accessible. Strange: I still don't find the Pioneer 104S in Device Manager.

         Nevertheless, this is the first problem: I bought a flight sim from UbiSoft "IL2" and although the CD spins up its drive and permits me to open its SETUP.exe, I always get a Windows error message from UBIsoft  Installer the OS tells me the product requires the CDRom for installation. I just can't get the thing to install from the CD to my pc.

So it's just no good that my CD/DVD is in 16 bit mode, but I don't know how to fix it.

System: a Soyo 6BA+iv (440BX chipset) mainboard with 512 MB SDRAM (pc133 cas2) P3-700E (at 960 MHz and 80°F).
         The CD is on IDE2, 20 GB HD is on IDE3. (ATA66 via Highpoint on board controller).
My BIOS is configured to consider my OS *not* PNP and the BIOS is automatically assigning IRQs. When I changed the BIOS setting to "OS *is* PNP" and changed IRQ assignment to manual, the system became unstable BUT it booted to Windows and I *did* see that the Pioneer CD drive was finally listed again in Device Manager.

         I was unable to maintain stability despite trying to change my Ti200 drivers to standard vga adapter. I had to drop my cpu out of overclock
         just to put things together again.
 Here's some basic IRQ info on my situation:

         IRQs]

         0 System timer
         1 Standard 101/102-Key or Microsoft Natural Keyboard
         2 Programmable interrupt controller
         3 Communications Port (COM2)
         4 Communications Port (COM1)
         5 NETGEAR FA310TX Fast Ethernet PCI Adapter
         5 Highpoint Technology Inc. HPT366 Ultra DMA 66 Controller
         5 Highpoint Technology Inc. HPT366 Ultra DMA 66 Controller
         5 ACPI IRQ Holder for PCI IRQ Steering
         6 Standard Floppy Disk Controller
         7 ECP Printer Port (LPT1)
         8 System CMOS/real time clock
         9 Creative SB Live! Value
         9 ACPI IRQ Holder for PCI IRQ Steering
         9 SCI IRQ used by ACPI bus
         10 Satellite Receiver PCI Adapter
         10 Intel 82371AB/EB PCI to USB Universal Host Controller
         10 ACPI IRQ Holder for PCI IRQ Steering
         11 NVIDIA GeForce3 Ti 200
         11 U.S. Robotics 56K Fax PCI
         11 ACPI IRQ Holder for PCI IRQ Steering
         12 PS/2 Compatible Mouse Port
         13 Numeric data processor
         14 Intel 82371AB/EB PCI Bus Master IDE Controller
         15 Intel 82371AB/EB PCI Bus Master IDE Controller

         [Hardware Resources]

         [Conflicts/Sharing]

         IRQ 5 NETGEAR FA310TX Fast Ethernet PCI Adapter
         IRQ 5 Highpoint Technology Inc. HPT366 Ultra DMA 66 Controller
         IRQ 5 Highpoint Technology Inc. HPT366 Ultra DMA 66 Controller
         IRQ 5 ACPI IRQ Holder for PCI IRQ Steering
         IRQ 9 Creative SB Live! Value
         IRQ 9 ACPI IRQ Holder for PCI IRQ Steering
         IRQ 9 SCI IRQ used by ACPI bus
         IRQ 10 Satellite Receiver PCI Adapter
         IRQ 10 Intel 82371AB/EB PCI to USB Universal Host Controller
         IRQ 10 ACPI IRQ Holder for PCI IRQ Steering
         IRQ 11 NVIDIA GeForce3 Ti 200
         IRQ 11 U.S. Robotics 56K Fax PCI
         IRQ 11 ACPI IRQ Holder for PCI IRQ Steering


         [DMA]

         2 Standard Floppy Disk Controller
         3 ECP Printer Port (LPT1)
         4 Direct memory access controller
         0 (free)
         1 (free)
         5 (free)
         6 (free)
         7 (free)
 
I'll do what you tell me!

Thanks, Dean