I have just been given a PC with win 2000 on it, when turned on gets blue screen of death "inaccessible boot drive", which implies problem with MBR, trying F8, and safe mode and all combinations doesnt work. I tried to cretae a boot disk with boot.ini,ntdetect.com and ntldr from my XP machine, but came up with a message that hal.dll was missing or corrupt , so no go that way, Does anyone have a plan how I can get in and at least try a format/mbr. Cant get a Cd in the drive as machine never powers up , (doesnt sem to have a pin hole to open it), so cant use my xp disc or linux
Help!!!!

You didn't mention a floppy drive so I guess there isn't any. If you have one somewhere, try to install it and boot w/ a 98 boot disk, run fdisk and fdsik /mbr
You could also remove the drive and put it in one of the external USB boxes and connect it to another machine. If the partition is still good, windows will give it a drive letter.

You don't run Fdisk to run fdisk /mbr, you just type it at the DOS prompt.

Duh!!! Did you read the original post??? He can't get to a DOS prompt, the machine doesn't boot!!!

" when turned on gets blue screen of death "inaccessible boot drive"...."
"Cant get a Cd in the drive as machine never powers up "

Huh?
It gives you the bsod but doesn't power up?Do you mean the "..machine never powers up.." ...into Windows?

In any case you should be able to go into your bios Setup and make sure the boot order has the CD drive before the hard drive, or, preferably, the floppy drive first, the CD drive second, the hard drive third, if you can do that.
If it is already set that way, or if you reset it that way and the 2000 CD will not boot, some 2000 CD's are not bootable, or some old CD drives cannot recognize a bootable CD. If that's the case, make the floppy set described below.

"I tried to cretae a boot disk with boot.ini,ntdetect.com and ntldr from my XP machine, but came up with a message that hal.dll was missing or corrupt , so no go that way"

That sounds like you have a working floppy drive.

If you do have a working floppy drive, there is a utility on the Win 2000 CD that can make a set of 4? floppies that can be used to start up Setup. You can insert the Win 2000 CD in any working computer and navigate on the cd to where the utility is (I don't have a Win 2000 CD to look at so I can't tell you where it is, but I know it's there) and use the utility to make the set of floppies.
You boot with the first floppy, and insert the rest in turn as they are asked for. When those are all loaded, at that point you can insert your Win 2000 CD.
Then you are best off to skip the first opportunity Setup gives you to Repair (which goes to the Recovery Console) - continue with Setup, then choose to Repair your present Windows installation - that will not erase anything already on the drive. You will need the Product Key for the Win 2000 installation, and the Setup will go pretty much as a Setup from scratch does, except you will be asked to supply a lot less information.

If you get messages saying can't find such and such a file, try cleaning the laser lens on the CD drive with a laser lens cleaning CD, and cleaning the CD itself. If you still get errors, either your legitimate Win 2000 CD is too scratched, or the CD drive is faulty, or you are trying to use a bootlegged copy of a 2000 CD that is on a CD-RW disk rather than a more reliable CD-R disk.