My computer consists of a PC100 System Board with all needed onboard/built-in features working; USB and Network Adapter built-ins remain untested. A SCSI card takes care of a Scanner. AMIBIOS version is Release 0601-1999S. Drive A is the usual 3.5 inch floppy. No Drive B. Drives C & D are partitions of a Quantum Bigfoot 1.2gb HDD jumpered as a Master and entered as a First master in the BIOS; C is 200mb, D the remainder. Drive E is the CD Rom, running as a slave to the Quantum. Windows 95b is installed on Drive D. I want to add an IBM 546mb hard drive, model DSAA-3540, to the system as a Secondary master. I believe I have the jumper right. There is no problem in getting the Bios to recognise it as such via the Auto setting. But having got this far, my system will not boot up: this turns out to be not surprising, as I can get far enough with DOS (and with Norton’s) to find out that my original Drive D is now Drive E, and the IBM HDD has become Drive D. The CD Drive has disappeared, but A & C seem to be OK. However, I can’t open Windows from my new Drive E as there appears an insistent message that Highmem.sys isn’t in the Windows folder. Which it is, of course.

The problem you are having is that your computer’s BIOS is set to boot up the computer from the D drive because that is the drive containing your operating system. Now that you have installed a new hard drive, which is assigned as the D drive, your boot up drive is demoted to drive E. Accordingly, your computer is trying to boot up on your new IBM 546mb drive because it has the drive letter of D (which your computer thinks is associated to the boot up drive). Since your BIOS recognises all of your drives, this makes life simple, because all you need to do is to go into your BIOS settings and in the ‘BIOS Features Setup’ (or alike) you should find something like ‘Boot Sequence’ where you can change the sequence and drives that your BIOS looks for, when booting up, for an operating system. For example, in your case the current setting would be something like ‘A, D’ but you would want ‘A, E’ since your hard drive containing your operating system is assigned the drive letter E.