NT4 workstation wont boot. When switched on, start up screens are normal - RAM count is fine and SCSI card & disc detected ok. Last line before it 'hangs' reads something like:- 'Searching for boot record from SCSI..OK'. After that, curser just sits in bottom left of screen and blinks. Critical info on disc but I (stupidly) don't have an ERD. Could FDISK/MDR help or hinder?

NT is not dos and fdisk/mbr is returning the mbr to dos mode. Not a good thing to do.

I would suspect a virus has removed your master boot record.

If you boot the nt cdrom via the bios or a cdrom boot disk you can do a 2nd install. You should be able to abort after the first reboot. The first phase writes the NT mbr info. After you see the bios screen start hitting your up or down arrow keys. This will stop the autostart of the second phase of the install. You should see the boot menu with your original install and the Upgrade/new install.

If a virus you may wish to continue the install [install to winnt2 not winnt or you will overwrite your original install] and buy/use a virus checker to clean the drive if a virus is the source of the problem.

Wanderer - fdisk /mbr & NT's setup both write standard Microsoft master boot record (as does fixmbr in 2k/XP recovery console) - so if it is a boot virus, fdisk /mbr as good as anything.

But the second install is a good idea - as it should also write a new boot sector. This sounds like a boot sector problem - which with NT you'd normally run a repair for - just check the boot sector to repair. You can try a repair without the ERD (it will try to find the installation - sometimes does/sometimes doesn't). If you have a 2k/XP/2k3 install CD, you can run recovery console from it (works with NT too) and try running fixboot (writes a new boot sector - NT can boot with 2k etc boot sector).

NT as well and W2K/XP modify the mbr to point to themselves. You use 9x/dos fdisk to do a fdisk/mbr and you have now altered the mbr NOT to load the boot.ini. It is the same thing you do if you want to get rid of a lilo boot. With the same results.

I usually recommend the 2nd install since you have the same amount of time involved for a repair. In addtition some folks get a bit exerberant and check all the boxes thereby returning the OS to the state it was the last time a ERD was done [or if never] to the original install. I don't take them down that path in an attempt to prevent this mistake.