My Windows XP computer has 2 IDE drives: one 8 Gb and one 20 Gb. I need to install Windows NT 4 on it to test some software. When I boot from the NT 4 install CD, it can't see the IDE drives, only the CD drive. I put in the diskette with the NT 4 SP 4 (> 7.8 Gb) version of ATAPI.SYS and select it as a SCSI/Mass storage driver. After loading the driver, the install says that the hardware supported by the ATAPI.SYS driver is not present in the computer. Since XP runs on this computer every day, I know that the hardware is OK. If I continue past this point, the install lists my two IDE drives and says that it needs to format my first drive. If I select Format, it then says that it cannot access the first drive and that install must exit. The computer has an ASUS P3B-F mainboard with a Pentium III CPU, 512 Mb of memory and an Award 1006 BIOS. I have read about problems with >= 256 Mb RAM and NT 4 and about problems with some older Award BIOSs settings. The ASUS website mentions the updated ATAPI.SYS driver. Anyone who solved a similar problem feel free to give me advice.

Primary Master partition - what is the file format there? It has to be fat16 for NT to boot in a dual/multi-boot. With '9x/dos it can up to 2Gig max. With XP/W2K (and no '9x/dos) again it must be fAT16 - but can be up to 4Gig; it cannot be fat32, nor ntfs5. Which drive do you wish to install NT4 to? Are you able/willing to install NT to its own physical drive? Post back details of current Primary partition size/format; also if willing to install NT4 to its own drive.

The primary master partition contains a mostly-empty 2 Gb FAT-16 file system where I wish to install NT. The problem isn't that the install can't recognize the file system; it is that it can't recognize either of the IDE drives at all. Normally, the NT install lists all drives it recognizes on its opening screen and asks you to type S to add more device drivers. On that computer, it only lists the IDE CD-ROM that it booted from. I don't mind just wiping the drive and starting over (XP is on the other drive, which I can remove or ignore), but that is pointless unless the install can see the IDE drives.

NeilO what you describe doesn't sound right. If this is the primary drive and XP is installed on the 2nd drive then either you should be concerned about wiping the primary drive since XP won't boot or this drive with the fat16 primary partition is NOT the primary bootable drive. So which is it? As trvlr points out NT requires the bootable drive, first drive with a active primary partition, file system to be fat16 or formatted in NT4 NTFS format to install. If you 20gig drive is slaved to the 8gig drive this can be a problem. Older less capacity drives can have problems controlling and addressing larger drives. Especially since NT uses older drivers. Always a good idea to reverse using the new larger drive to control the smaller older one. Or best yet have each on its own ide channel so you don't have to deal with that issue. If NT sees the drives and wants to format them or the primary this means it is not seeing a partition to install to or launch from. Sounds like your bootable active primary partition is not fat16.

I asked a friend about this problem and he said: 1. Copy the file \WINNT\System32\drivers\atdisk.sys from a NT 4 SP 6a install to a floppy . 2. Boot DOS on the computer with the failed install. (Luckily, I had installed DOS in order to run the NT install, so my drive was bootable as DOS when the install failed). 3. Attrib the DOS + NT install partition to -r -h -s with the command ATTRIB /s -r -h -s *.*. 4. Copy the atdisk.sys file from the floppy to the $WIN_NT$.~BT and $WIN_NT.~LS directories. 5. Repeat steps 1 - 4 with the atapi.sys file. 6. Copy the atapi.sys file also onto the NT 4 SP 4 atapi.sys driver install disk downloaded from the MS website. This updates its service pack 4 atapi.sys driver to service pack 6a. 7. Reboot to the failed NT 4 install. 8. When it says press F6 for additional drivers, press F6. 9. Press S to select a new driver. Install the driver from the ATAPI.SYS diskette mentioned in step 6, above. I don't understand why I had to do this since I had copied the file myself, but it wanted it to be installed again. 10. Press S again and select the IDE CD-ROM driver from the list of additional drivers. 11. NT 4 installed fine after all this. The procedure wasn't as long as it looks from this description--it took about 10 minutes to get the install started. My first drive had a Windows XP install on another partition at the end of the drive. My friend said that the NT 4 install CD "freaks out" if any drive on the computer contains a partition that ends after the 8 Gb boundary and that is why it said it couldn't see either of my drives.